"Class dismissed."
Professor Snape fell back into his chair as soon as the last idiotic 6th year left his dungeon classroom. After a few minutes of closing his eyes and breathing slowly, he sat up straight and looked indifferently at the pile of test papers on his desk.
He picked them up to take them to his office/living quarters and half-turned before a Slytherin-green piece of paper folded in half caught his eye. He put the papers down to the right of the mysterious green whatever-it-was and reached cautiously to pick it up, expecting it to explode as a prank from the Weasley twins.
It didn't explode as he touched it, neither did it do anything. It was just an ordinary piece of paper. He quickly examined it from every angle, just to be sure, then sat back in his chair and opened it.

This is just because I couldn't keep it secret any longer. The thought of keeping it within me and not having anyone to tell who would understand, filled me with dread and made my stomach feel like it was rolling around in my body.
Anyway, getting to the point.
Professor Snape, I think I love you.

~ Your secret, yet in a way, not so secret, admirer x

Snape stared wide eyed at the letter. He had no idea how to react to this type of thing. Many thoughts rushed into his head:
This was most likely the work of a student. They had called him Professor, after all.
Therefore this had to be a joke.
But what if it wasn't a joke?
Of course it's a joke, who would love me?
What if someone is attracted to unemotional, student-hating Slytherin professors?
Don't be ridiculous, who would be attracted to that?
There will be someone...
There won't be many, so what's the possibilty of meeting one?
It could happen.
Who am I kidding? I've haven't been attracted to anyone since Lily. Well... unless that includes...
No. Be quiet.

Snape again picked up the test papers and put the note on top and entered his room. But instead of marking them, he fell onto his bed and slept until morning.
First lesson was with his 6th year Gryffindor/Slytherin class, the same class as last lesson the day before.
"Quiet!"
The class obeyed.
The lesson went by fast. Snape made Longbottom try and answer questions to amuse himself. But he couldn't help but notice that Potter hadn't done anything out of line yet. Snape eyed him suspiciously, but a bubbly feeling in his chest stopped him.
What was wrong with him? He knew what was happening but he didn't know why.
In the next lesson with the same class, Harry was still as well-behaved and hard-working as the last time.
Snape again taunted Neville and spent some time looking over Harry's shoulder. He studied Potter's work, not finding a single mistake in it, but he also took notice of Potter's writing. It was different to the letter, but he crossed his t's and dotted his i's the same. Of course he could've purposely changed his handwriting for the letter so Snape wouldn't recognise it.
Harry knew Snape had been standing behind him for at least ten minutes now.
"Something wrong, Professor?"
"Hmm? No, Potter. Get on with it!"
He briskly walked away and shook the thoughts out of his head.
That night he again found a green slip of paper with the same handwriting as before.

Professor,
Over the past couple of days, I began to regret my decision to tell you.
After all, I am a student, you are a Professor. A rather sexy one at that, mind you.

Snape felt his inside clench and his cheeks go red.

Also, judging by what I know of you, you don't seem the type of person to be in a relationship or express any "nice" emotions. I'm sorry if that's not the case, but you do come across like that. And yet I'm still in love with you. Sometimes I think there's something wrong with me for liking you, but I couldn't care less.
I do love you, of that I'm certain.
I would really like it if you could reply to me, to tell me if I'm wrong about anything? Or maybe tell me if you like anyone at the moment? And your sexual orientation? Sorry if I went too far there.
I don't know. Don't feel obliged to.
If you do, just leave it behind one of the portraits outside the Gryffindor common room (yes, I am a Gryffindor, which makes it even less likely for you to like me back, I know), and don't wait for me to come and get it, because then I won't be secret anymore.

~ Your increasingly not-so-secret Gryffindor admirer x

Snape fell back onto his bed, utterly gobsmacked. This Gryffindor student was sure that they were in love with him- a Slytherin Professor of whom they got the description spot on.
Against his brain telling him not to, he wrote a letter to the mystery student, hoping it was who he wanted, snuck out at night and placed it behind a portrait by the Gryffindor common room. But against the letter's warning, he stayed hidden, watching for anyone. He waited for ten minutes before he thought he saw the portrait move slightly. But he blinked it off as his tired eyes twitching. After another twenty minutes he decided to quit and went back to his room to get as much sleep as he could.
Harry got back into his bed and tucked his invisibility cloak underneath it. Then he opened the yellowish-white parchment he had found under a sleeping portrait.

Look, whoever you are, I'm flattered that you feel like that, though I am rather uncomfortable about it. You are right, I am the sort of person who would not be in a relationship, not because I do not want to be, but because I am a very awkward person around other people. This usually holds me back from getting to know people and vice versa.
To answer your second question, yes, I do like someone at the moment. But it is illegal as this person is a student, and I cannot believe I'm saying this but, I really hope that student is you. And yes, that means this student is a Gryffindor.
It actually took me a while to get to terms with my feelings towards this particular student, for reasons that are obvious if you know/are the student.
And to answer your third question, I have been out as homosexual since I was nineteen, so I really hope that if you're not the student I like, that you are at least a male.

-SS

Harry stared at the parchment with his mouth hanging open. Snape could actually like him. He was in Gryffindor. And it would be perfectly understandable for Snape to be confused and reluctant about liking him. Though I suppose there could be many other Gryffindors who Snape has a problem with. Which was all Gryffindors.

The next lesson with the 6th years came the week after.
"Today we will be making the redolence potion. If made correctly, it will turn a certain colour depicting your current mood caused by things surrounding you. I will come around the classroom once your potions are made and tell you what you colour means."
After thirty mintues Snape looked around the class to see if there were any Gryffindors he could interrogate when he spotted Harry Potter chopping faun grass with what looked like determination. He was working at the same pace as Hermione Granger, and they were both 10 minutes ahead of where he'd expected the class to be by now.
"Potter!"
"Yes, Professor?"
"Don't play innocent with me, boy. Why and how are you working so fast?"
"I... I just am, Professor. You told us to make this potion, so I'm making it. Am I doing it wrong?"
"Ridiculous! You must be taking something to put on the level of Granger here. You've been acheiving the same marks as her for the past week now!"
"No, sir. I'm really not."
"I will leave it for now, Potter. But if I find out that you have stolen one of my potions you will be having detentions every day for the next year!"
Snape didn't know, but Harry wasn't very threatened by this, he would like to spend more time with Snape, and the only way to do that was detention.
"Professor?"
Snape sighed, "Yes, Potter?"
"You didn't say if I was doing it wrong."
"No, Potter, you are...", he bit his lip, "you are doing it fine.", he mananged to spit out and stormed away to pick on Neville Longbottom.
"What was all that about, Harry?"
"I really don't know, Ron."
"What an old git."
Harry felt like opposing this point, but he didn't want to act suspicious, so he just silently nodded.

"Silence!"
The class again obeyed.
"By this time your potions should be ready. Five points shall be taken from each person who's potion is not ready."
Snape started at the front of the class where the Slytherins were sitting and worked his way up and down the columns.
"Malfoy- black, arrogance."
Malfoy sneered at this.
"Crabbe- brown, confusion and stupidity."
Malfoy and Goyle both laughed.
"Goyle, yours seems to be brown too."
At this he stopped laughing, but Malfoy continued.
He made his way to the Gryffindors.
"Longbottom- yellow, fear."
Neville whimpered and Snape sneered.
"Finnigan- orange, humour. Think something is funny, do you?"
"No, sir."
Snape glared at him.
"Brown- white, obsession and admiration."
She giggled.
"Weasley- purple, annoyance."
Weasley smirked as soon as Snape wasn't looking at him anymore.
"Ronnie-kins, who are you annoyed at? I hope it isn't me.", Lavender whined.
Ron just shook his head and she went silent.
"Potter-", Snape looked uncomfortable and surprised at Harry's cauldron, and passed it without saying anything else, coughing before he spoke to Hermione.
"Granger- green, envy."
She stayed quiet.
"Hey Hermione?"
"Yes, Ronald?"
"Who are you jealous of?"
"No one!"
"Miss Granger! I would appreciate it if you didn't shout in my lessons. Ten points from Gryffindor, as well as the fifteen taken from unfinished potions."
The Gryffindors groaned and the Slytherins snickered.
"And ten points from Slytherin for the two unfinished potions."
All of the Slytherins' smiles dropped at exactly the same time.
Snape turned to see one smiling Gryffindor staring at him in a daze.
"Potter!"
Harry snapped out of his trance-like status.
"Detention after class!"
Harry hid his smile and nodded slowly.

The class left and Hermione and Ron gave Harry looks of apology before they closed the wooden doors.
"Wait there, Potter."
Snape went up to his room and came back two minutes later with loads of dirty cauldrons.
"Right, Potter. You will clean all of these cau-"
Snape eyes caught sight of something green on his desk, sticking out from under some 4th year test papers. His heart started to beat a bit harder.
"Something wrong, Professor?"
Snape opened his mouth to talk but instead just waved his hand in dismissal at Harry, signalling him to shut up.
He picked up the green card and looked at Harry suspiciously. Harry looked back at Snape in confusion.
"Get to work on those cauldrons, Potter. I expect all of them spotless in an hour."
"Yes, sir.", Harry said with a bit too much enthusiasm.
Snape sat at his desk and opened the letter.

Professor,
I'm sorry to hear that you are uncomfortable with getting close to people, though you want to. But this has just made me more determined to get to know you better and get close to you.
Interesting. I suppose you're not going to tell me who this student is?
And don't worry, no one shall be told about you liking a student, I promise.
Thirdly, that's the news I was hoping for. Yes, I am male and obviously, due to my previous letters, I'm gay too.
I'm in two minds of whether to tell you who I am or not. What do you think? By now I'm certain you've got a clue as to who I am, whether that be the guy you're hoping for or not. And of course even though I'm trying to differ my handwriting from my normal one, it still looks quite similar.
Please write back.

~ Your gay Gryffindor admirer x

Snape smiled at the letter, but quickly frowned again as Harry looked up at him with curiosity. He watched Potter clean his fourth cauldron thouroughly and his heart fluttered. He remembered how hard it was to admit to himself that he was attracted to Potter, and still struggled with understanding why.
"Professor?"
"Yes?"
"You've been looking at me for a while now. Why?"
"Because, Potter! Those cauldrons aren't cleaning themselves,", though they could, Snape thought and mentally smirked, "get on with it!"
Snape turned away and silently shouted at himself. Harry smiled and scrubbed the cauldron harder. Even though he thought he loved Potter he still had to act like he always had around him. He was nearly positive that it was Potter writing the letters, so Harry must be a good actor, acting confused, innocent and clueless all the time even though Snape knew he was smarter than most of the idiots he taught.
After the hour was up Snape walked over to see how Harry had done. There were still two cauldrons left.
"Alright, Potter. You can leave now."
"But I haven't finished cleaning."
"It's fine. You can go."
"I could stay and finish if you want me to..."
"Whatever you want, Potter, just hurry up."
Harry quickly went back to scrubbing the second last cauldron and finished both in five minutes.
"See you tomorrow, Professor."
Snape grunted. Harry was being too nice for him not to be the one writing the letters. That was the only way to explain the complete change of attitude towards him and the lessons.
Snape wrote a reply to the letter and went back to the same portrait to hide it. Then he hid closer to it this time, and watched for any movement.
Fifteen minutes passed before he saw the portrait move up at the corner. This time he had to act on it. He ran as fast and as quietly as he could.
Harry quickly put the letter under his cloak and opened it.

Apologies in advance.

-SS

Harry looked confused, but didn't have much time to think about it because he was pushed against the wall by a tall, black figure. He cried out in shock and at the force used to push him, but suddenly went silent as his cloak was pulled off.
Snape stood with his arms pressed against Harry's shoulders, keeping him from escaping. He stood catching his breath before Harry spoke.
"Professor?"
"Yes... Potter?"
"Am... Am I the student?"
Snape waited until his heavy breathing had went back to normal and his cheeks had reached the reddest they could possibly go before answering.
He closed his eyes tight, "...Yes.", Snape breathed with anger and what felt like relief.
Harry tensed and Snape thought he was going to try and escape, so he let go of Harry's shoulders and hung them down at his sides in defeat.
Harry's insides went warm and his heart started beating faster.
"Professor?"
Snape turned back to look down at him, then he froze as Harry's lips pressed against his and his arms wrapped around his neck. Snape was, as predicted, uncomfortable. But the feeling of finally kissing Harry was too much to give up, so he gave in to temptation and kissed Harry back, moving his lips around Harry's.
Harry's tongue traced where Snape's lips were closed and Snape opened them obediently. He could feel Harry smile at this and then slip his tongue into his mouth, caressing his tongue with his own.
Snape pulled away. "Potter..."
"Professor?"
"We can't do this. As was previously said, you are a student and I am your Professor, nothing more.", it sounded like it pained him to say it.
"So teach me, Professor.", Harry said seductively while running his hands down Snape's chest.
Snape groaned. "You know I would love to, Harry." Harry gasped at his first name being uttered from the mouth of the Potions Master, "But the rules..."
"Who cares about the rules? I am willing to accept the consequences if they should come."
"Go to bed, Potter."
Snape pulled completely away and walked quickly down the hall, thinking how lucky it was that none of the portraits woke up and about what he had just given up. He heard footsteps behind him.
"Potter, what did I tell you?"
"I'm sorry, Professor, but I've waited too long for this only to be rejected by someone who actually likes me back."
Snape sighed. "Harry... we can't."
"We can.", Harry cupped Snape's face and stood on his toes to kiss him. Snape kissed back again. "See, you want it."
"But I can't have it. It's against the rules. If someone catches us-"
"No one will catch us. You can just give me more detentions and we can use that time to be together, no one will catch us then."
"I don't know."
"Please? You know you want to.", Harry stroked down Snape's chest again, making him shiver.
"Fine, Potter! But this won't just be a short term thing, as bewildered as I am to why, I still think I love you, so this will be long term or nothing at all."
"That's what I've wanted for a while now, Professor.", Harry was sure he saw Snape smile, but it was dark, so he couldn't be sure.
"Now, Potter. Go to bed, I'll see you in the morning. And remember to act the same in lessons!"
"Of course, Professor."
After Harry was out of sight, Snape slumped against the wall, thinking about the worst possible outcomes of what he just agreed to.