This is after the Harry Potter event. They are both students of Hogwarts after Harry Potter left school.

Morgan Schneiderlin as himself
House: Slytherin

Emma Stone as Andrea Price
House: Ravenclaw

Wizards change
Before the academic year starts, the Professors of Hogwarts return to the campus to prepare for the year ahead. Andrea Price, Professor of Ancient Runes, was surprised to find a familiar but completely unwelcome face in the midst of the new Professors. The new Charms professor, Morgan Schneiderlin, was Andrea's worst enemy.
Morgan lived up to the negative stereotypes of his house - Slytherin. He was a bully who picked on her and looked down on everyone else. It was a wonder he never got killed during their school days; afterall, she wasn't the only student he had pissed off. He talked the talk, and disgustingly enough, he actually walked the walk. The guy was brilliant, but he was also rotten.
"Andy!" Morgan greets her with a wide smile.
"Thank's not my name." Andrea gritted through her teeth, ignoring the open arms Morgan had.
"Won't you come hug an old schoolmate of yours?"
"No."
"Oh don't be a child." He said, motioning for her to come closer. "Headmistress McGonagall said to give us newbies a warm welcome."
Andrea mouthed a spell under her breath and her wand moved quickly.
"I don't think McGonagall meant it literally." he said as he felt a warming spell being performed on him. Andrea flicked her wand and he felt things go back to normal.
"Andy, I wanted to - "
"It's Professor Price to you." she said haughtily.
The smile Morgan had turned into a scowl over her attitude.
"And unless it has to do with my Ancient Runes class, I don't want to talk to you." She said and walked away, her robes billowing.
They didn't talk again that night, Andrea wouldn't let it happen.

During the Great Feast Andrea was annoyed that Morgan decided to sit to her right. Professor Trelawney, sitting to Andrea's left, happily encouraged Andrea to talk with the new young Professor, along with a nudge and a couple of winks. She wanted to scream to Sybil that just like her predictions, Andrea talking with Morgan would not happen.
Since the students were in front of them, Andrea was left to try and ignore Morgan's small talk and play with her food.
"I forgot how good the food is here." Morgan said, the 9th remark from Morgan that Andrea has ignored for the night.
"Andy, come on. You're saliva must be rotting. Say something."
"You're disgusting." She said before taking a sip of her pumpkin juice.
"At least you replied to me." He smirked. "Are you excited for the start of class? I am. First time teaching." He shared.
Andrea's curiosity was piqued. Student Andrea would have never pegged him for one to become a teacher. She probably thought he'd become a bully.
No, that's not right.
Morgan may have been a horrible guy to her who teased her mercilessly but his brains wouldn't have let him be just a bully. He was too smart to be reduced to that. If he was not a die-hard Slytherin then she would not surprise if he went to Ravenclaw, just like her. He was more intelligent than a lot of Ravenclaws - she had to admit and his grades were too perfect for all the students in the same year and of course for a bully. Like a male, Slytherin, mean and merciless Hermione Granger.
She wanted to ask him what he was before becoming a teacher. What urged him into this profession. But her pride wouldn't let her make those questions, no matter how curious she was.
"Don't scare the kids. You're handling first years; several of them are muggleborns. Don't belittle them if they're not immediately comfortable with magic."
"You sound like that's from experience." He jokes. "Who did you scare?"
"A bully from Slytherin house who kept reminding me of that one time I screamed bloody murder when I first saw Peeves, a poltergeist, something that didn't exist in the first 10 years of my life."
Andrea noticed that Morgan looked mortified, his face a little sallow.
Good, she thought.
"Merlin. Andrea, about that. I wanted to - "
She turned her back to him and forced Sybil Trelawney into a conversation. Andrea had practice with ignoring people; she had extra practice ignoring Morgan.
Flashback
Before coming to Hogwarts as a student, she got mercilessly bullied by her schoolmates in her little town. She was a bookworm who preferred to read thick books with no pictures while her classmates ran around the playground; she said weird things for a child her age and her classmates didn't understand her; and to top it off, weird things happened when she was around. Like that one time her schoolmates couldn't go down the slide or when, no matter how hard the kids pushed, the swing wouldn't move.
It wasn't until she received her Hogwarts letter that her father explained a possibility to her "strangeness"; something he never thought of until that letter arrived.
Her father was a squib, a wizard-born non magical person. After being spurned by his family, he moved to a small town where he met her mother, a muggle. Together they lived a peaceful life, void of any magic. Until Andrea. Her father didn't think that with their blood, she would have any kind of magic and just shrugged off the strange occurrences that would happen once in a while.
So when the letter arrived, and after being explained what it meant, Andrea was excited for the new world, until she set foot in the new world. It was a little overwhelming for an eleven year old girl. The Magical World scared her in the beginning. She was barely adjusted to some of the concepts of the Magical World when school started, so when she first met Peeves prior to the Great Feast, she had a little fit. Morgan and his posse never made her forget that; and reminded her how inadequate she was as a witch.
But her brilliant mind and eagerness to learn helped her adapt to her new surroundings. Backed by her knowledge and new skills, she gained confidence. She learned to ignore other's opinion of her and move on and past them.
She was better than what others thought of her, she reminded herself.

The first months of the school year were a blur. Morgan and Andrea didn't cross paths much. Andrea tried to be as far away from him as possible whenever they weren't required to be in a room together. Morgan, on the other hand, tried to spend as much time with her as possible.
He sat beside her during meals; he brought her food when she overstayed in her class preparing for her next lesson; and he helped find her kneazle whenever he tended to wander off, as he tended to do.
Andrea saw this as just another way to get under her skin.
End of flashback
During the Halloween gathering set for the Professors, Andrea was shocked to find that most of her co-workers were flocking around Morgan, laughing as if what he had to say could be interesting.
She had flashbacks during her years at Hogwarts when Morgan, surrounded by his posse, would make fun of her.
Andrea moved towards the refreshments table and did something completely unusual for her - she drank some of the spirits available. It didn't take long before she started feeling a little sick.
"Andy!" She heard that nickname again and her blood boiled.
"That's not my name." Andrea growled barely audible.
"You're drinking all by yourself? You could have called a friend to share some." He said, picking up a half empty bottle of firewhiskey.
"You're not my friend."
"Ouch. You're hurting me, Andy." Morgan said, a hand over his heart.
"That's not my name. Stop calling me that." She said, slapping away the hand he had placed on her forehead.
"You look a little green. Are you ok?"
"I'm fine." She said and took a step back only to stumble a little.
You don't look fine."
"Fine! I'm not 'fine'!" She said, raising her voice. "I'm sick!" She cried out and the room turned towards her and Morgan. "Sick of you! You and your pretentiousness. You sicken me. You smile and charm them - the professors, the students - but I know you. No matter how smart you are, you'll always be a bully."
She finished her tirade and the room was silent.
Andrea heaved and she covered her lips but she couldn't stop the bile rising. She tasted the bitterness of it before it was all over the floor. She could make out McGonagall give orders to Madam Pomfrey and Morgan's voice rise over the other but it all sounded like they were underwater.
She looked around by the room started spinning and then things went dark.
A good while later
She woke up in the infirmary, with only one other occupant, a student still sleeping on the other side of the room.
"Andrea! Good to see you awake. How are you feeling?" Madam Pomfrey asked.
"A little queasy. My head is throbbing."
"I'll get you a pepper-up potion. I'll be right back. Minerva will be here soon."
Andrea groaned. She felt like a kid about to be reprimanded by her headmistress; which wasn't too far off from reality.
Madam Pomfrey gave her the potion and let her rest, though that didn't last long.
Minerva came in and fished over her and her conditions, having never seen Andrea act that way. After making sure she was ok and reprimanding her over her actions, Minerva broached a topic Andrea wanted buried.
"Andrea, I also wanted to talk to you about Professor Morgan Schneiderlin."
Andrea sighed but held her thoughts to her.
"I remember how Morgan was like when he was a student here. He wasn't the role model Professors would like all students to be, of course except for his intelligence." Minerva started. "And I recall now that there were some instances between you and Morgan and that there may still be bad blood between you two."
"We hate each other since Year One." Andrea summarised.
Minerva shook her head. "He doesn't seem to hate you."
"He does. He just doesn't show it. To him I'm still that daughter of a Squib and muggle who somehow got magic passed down to her because of a fluke. The freshman who got scared when Peeves pulled pranks on her. The know-it-all with her head in the books, he made it like he was NOT another know-it-all, like I WAS a stupid girl who pretended to be smart. The overachieving student who hoped to prove that she's no less than the others, that I'm not an anomaly."
"Andrea, I wouldn't have hired him if I thought he was a bigot." Minerva McGonagall pointed out. "He was a kid then, he IS a man now."
"Somethings don't change. He's a merciless Slytherin through and through. He's just playing you. He's still mean, deep inside."
"His student don't think so. They like him."
"That's because they're either blinded by his smile or intimidated by him." Andrea rolled her eyes.
"You noticed his smile too?" Minerva asked. "It is pretty nice."
"He's also a bully, he's stuck up and he's annoying." Andrea said, ignoring the teasing smile the headmistress had.
"Who has he bullied recently? I haven't seen him bully or head reports about that. Stuck-up? The guy who pulled your hair back while you puked? The guy who soiled his shirt just to carry you to the infirmary immediately? The guy who helps muggleborns with their flying lessons during his free-time or agrees to play quidditch with the younger students, even those who are Gryffindors?
"He's annoying." She huffed and crossed her arm, aware that she was making a poor argument.
"I think he's only annoying you. You are the one he spends most of his time with - or at least tries to. The other witches wouldn't mind his attention."
"Minerva, I think you've been talking to Professor Dumbledore's portrait." Andrea pointed out to which McGonagall smiled.
"The wizard has been trying to extend an olive branch, but you won't even let him finish a sentence."
They look towards the doors when they hear footsteps echo. Morgan's athletic form was recognisable in the distance.
"Speaking of..." Minerva trailed off giving her a knowing smile.
"Minerva, please."
"Let the wizard talk, Andrea. I know Ravenclaws think they know everything but there's always something new to learn. Good morning Morgan!" Minerva greeted the new addition.
"Good morning Minerva." He greets the headmistress before turning his attention to Andrea. "Andy- Andrea," He corrects himself. "How are you feeling?"
McGonagall cleared her throat when Andrea didn't say anything.
"Better, thank you." She says.
Morgan nodded and then silence.
"I'll leave you to it. Morgan, look after our patient." Minerva bid them goodbye and left.
A couple of heartbeats passed before the silence was broken by Morgan.
"You don't drink? Never saw anyone react to alcohol so quickly." He said.
"No, I don't drink." She replies curtly, not making eye contact.
"I brought you breakfast." He said, opening the satchel he was carrying.
"You didn't have to do that. Minerva's gone. We can stop pretending we're friends. You don't have to act so nice, I know it's against your nature."
For the first time since they reunited, she saw Morgan's face darken, he actually looked angry.
"For a know-it-all, you know nothing." He said. "We're not kids anymore Andrea. I'd like for you to see that. Even wizards change."
"Other wizards might, you didn't."
"And how would you know that? You look at me and still see that 11-year-old child who called you names and laughed at you. Look at me."
"I don't want to." Andrea slapped his hand away. "I want you to leave."
"Well tough luck! I am not leaving. I'm saying my piece and you're going to listen to it and then I'll leave and we can move on with our lives. I'm sorry." Morgan said. "I am sorry. For how I treated  you when we were kids. I was young and thought I was King of the World, that the world was mine to rule. I didn't understand that words were hurtful, hurtful to you when it made other people laugh and pat my back. I'm sorry I made you doubt yourself. I understand why you didn't like me - I was a prick. I hope one day you can forgive me for how I was and see me for who I am now." He paused waiting for a reaction from her but got none.
"I have wanted to apologise to you since we graduated." He clarified. "I'm sorry to have bothered you Professor Price. I wish you fast recovery. Goodbye." He pulled out a bagel, an apple and tea - her usual breakfast - from his satchel. He set it on the side table before turning away and leaving.
Andrea took the day to reassess her actions towards Morgan. Since they have met a few months ago, she had always treated him with hostility. How could she not? She still remembered every remark he had ever snarled at her, or how he made fun of her and her parents, how he had embarrassed her in front of the whole Hogwarts' students. But when she thought about his recent actions, she couldn't remember them being mean or hurtful.
Sure, he still tended to come across cocky but he never said or did anything intentionally hurtful. In fact, he was opposite. She remembers the good things he did for her, and how she had turned her back to him over and over again.
She was the ass now.

Flashback
Actually, during their school day, there were not just Morgan being mean to her and many other students. Andrea had saved him once, like saved his life.
In their seventh year at school, during their break, she was walking down the corridor. There was no one there. Andrea stopped when she heard voices. She hid and listened.
" You are so weak. Why didn't you find out about that monster you imagined yourself?"
" Definitely Schneiderlin's voice. " she thought.
" What if it kills me. Can you go and take a look with me?I'm sure it was down there." another boy who she figured out as Jay Leno, Morgan's friend, said and pointed to the stairs lead to the corridor down there.
" In Hogwarts, everything is safe. You will never get killed. Not that I was scared, I refused because I don't believe your bullshit. The noise that we heard came from the wind outside not from some monsters, today is a windy day and there are a lot of windows down there, I'm sure about it. The ghosts here will never harm or scare us because of Professor McGonagall's order. Ok?" Morgan snarled.
"..."
"I can't believe I have a guy who I called friend that stupid, weak, ungrateful and..." Morgan began.
"SHUT UP YOU TWAT! You think just because you are smart, strong and popular doesn't mean that I am your puppet and for you to bully, to mock. I thought we are friend, but no."
"Yeah. You are just like Price. Stupid and weak. You screamed like a girl when you heard those noise..."
Hearing that, she felt the anger rise up. How dare him talk about her like that!
Then she heard a spell had been performed and a yell. She dared to look. Her eyes widen when she saw Morgan falling off the stairs and heard Leno murmured: "That's what twat got." He walked away. She ran to Morgan who was lying on his back downstairs. Despite all he did, she still worried for him. He was unconscious. There was a wound on the left side of his forehead. There were some cut and bruise beneath his torn uniform and he probably had some broken bones too. Some of them were caused by the spell, some of them were caused by his massive fall. Blood trickled down from his wounds. She took out her wand and began to heal his wounds. She saw the blood began to come back to the open wounds (Sorry about my English, just imagine it like when Snape healed Draco). After a while, all the serious wounds were gone, all the broken bones were fixed. There were still some minor cuts and bruises through. After that, she went to find Mrs. Pomfrey.
End of flashback

"I would like to talk to Professor Schneiderlin." Andrea told the portrait serving as the doors to Morgan's quarters.
"Whom shall I say is waiting?"
"Andrea Price."
It took only a couple of minutes before the portrait swung open and let Andrea in.
"What can I do for you Professor Price?" He asked, his attention on the paper he was holding.
"Morgan,"
Hearing her call him by first name caught his attention.
"I wanted to thank you, for your apology late as it was. I wanted to say I appreciate your apology. I can't however forget that incident but maybe you could teach me to forgive you."
"How?" He asked.
"First, by being the bigger person and forgiving me for the horrible way I treated you. I never thank you for what you did last night, for bringing me breakfast and coming to check-up on me today; for helping me find my kneazle over and over again, for so many more things you did."
"Forgiven." He said, without hesitation.
"That easy?"
"Yes. You had saved me once anyway" He said.
"You know?" Andrea asked surprise. "But you were unconscious"
"Well Minerva told me after I brought you to Pomfrey. She called it a repay for what you did to save me. So I asked her to tell me everything about that day." he explained.
She chuckled.
"Is 11-year-old Morgan forgiven?" he asked
"Not yet." she replied honestly. "I'd like to get to know the man Morgan; to replace the 11-year-old snotty Morgan I know."
"Sure, we can do that."
"This is too easy." Andrea said, a little embarrassed.
"Slytherins do what we have to do to get what we want."
"And what is it you want?"
"To leave the past in the past. To, maybe, be friends? Or at least have someone to converse with during meals."
"I'm pretty sure the entire faculty would be more than happy to talk to you. What is it that you talk about?" She asked.
"Sit down and I'll tell you." He says.
"Oh no! I don't want to take too much of our time. I see you are busy." She said.
The tips of Morgan's ears turned red. "This is nothing." He said shoving it aside. "I just staged this to look more..." he moved his hands about, embarrassed at his confession.
Andrea snorted and took a seat.

By the end of the school year, Andrea and Morgan had become good friends, nearly inseparable. The teasing between them continued and while Morgan still called Andrea 'Andy' at times, she got to call him 'Morgana' back, referencing to a picture of him where he was wearing a Hogwarts female uniform, complete with pigtails.
Minerva still gave her these knowing looks whenever she walked past Andrea and Morgan together. She also liked telling Andrea how she's not seeing what's in front of her. In the beginning Andrea just shrugged them off and kept repeating to the headmistress that she must stop gossiping with Albus Dumbledore's portrait, but more recently she's been feeling a little self-conscious.
One day she woke up and realised Morgan was a man, a very good looking man with whom she shared several common interests with. Unfortunately, Morgan didn't seem to reciprocate her feelings. 
"So how did you find your first year of teaching?" Andrea asked Morgan as they took tea by the Lake.
"Fun. I really enjoyed this experience. I'm looking forward to doing it again next year." He said. "Although I'm really tired and can't wait for a nice vacation."
"Where will you be going?"
"Somewhere where there is the sun and a beach."
"I see." Andrea's mood taking a dip realising they'd be separating for the vacation.
"Where will you be?" He asked.
"Visiting the family." She replied. "That sounds lame compared to sun and beach."
"You could always come with me after you spend some time with your parents. I wouldn't mind seeing what you have under those robes."
"Oh shut up Morgan." she pushes him away.
"But I'm serious, you're more than welcome to join me and my mates to the beach. And I really wouldn't mind seeing you in a bathing suit."
Andrea shook her head and finished her tea.
"Ah Andy. For a Ravenclaw, you really don't know much."
"Hm?"
"I'm trying to flirt with you." Morgan said leaving Andrea surprised and blinking rapidly trying to gather her thoughts. "Merlin. That came out wrong. Am I a Slytherin or a bloody impatient Gryffindor?" He asked himself the last part.
"Morgan?"
"I've been trying to be subtle and let you come to me but my time is running out so...I'm going to do something very un-me. Something that's going to turn Salazar Slytherin in his grave. I'm going to be a brave, impulsive Gryffindor and ask you something, would you like to have dinner with me once we're out of Hogwarts? I want to say thank you for saving me when we were 17 and for forgiving me of what I did, I also want to get to know you better?" Morgan asked.
"I'm going to be very Gryffindor too, leave my rational mind behind who's screaming the statistics on dating a friend and a co-worker and say yes. I would love to have dinner with you."
They stared at each other, processing what just happened.
They both burst out laughing together and joked about how they should take out the sorting hat and see if they would be sorted in their respective houses once again.
"Minerva must have gotten to me." Morgan said.
"Minerva?"
"She's been pushing me to ask you out for months."
"What? She's been telling me to open up my eyes and look at you before you looked at another witch." Andrea confessed.
"Did Minerva McGonagall set us up?"
[end]

Notes:
This is in fact not my work. I found that on tumblr so I post it here for everybody to know about this wonderful story. I did add something new on it. If you want to read the original one, just google: morgan schneiderlin fanfiction. Yes. I want to thank the writer of this wonderful fic. You may accuse me of copyright but I want to add something new for this chap. Yes Morgan Schneiderlin one and only: