No one ever told Harry Potter about sex. No one ever really thought about it, because no one ever really told Harry Potter about anything, before he came to Hogwarts. So it was at Hogwarts that he began to learn everything he needed to know.
He couldn't sleep the first few nights in the Gryffindor dorms, the sounds of other people breathing, moving, snoring, mumbling in their sleep keeping him awake far past lights out. But once he'd sorted out those sounds, got used to having a frighteningly cavernous space around him, the bed that was big enough and soft enough and bug-free enough to keep him asleep right through the night.
The only time he was kept up after that was when someone near him made noises that he didn't filter out, and that someone near him was usually Ron. It started with a scritch against the sheets, more regular than random night-time movements, then rapid breathing out of time with the scritches.
By that point Harry's eyes became accustomed to the dim light and he could see Ron's covers moving, could see exactly where his hand was, what he was doing. Could watch the rhythmic strokes up and down, faster and faster, louder and louder.
Ron had five older brothers, Harry knew. Five brothers who'd probably all done the same thing, brothers Ron had learned this from. And if all of them did it, then probably everyone did.
And so Harry learned how it was okay to touch himself.
Hermione always insisted they go to the library to study, because the Gryffindor common room was full of 'disruptive sorts' -- which the Weasley twins firmly denied -- and then would leave Harry and Ron at a table and disappear in pursuit of the perfect source to propel her essay from adequate to excellent. Adequate had always been enough for Harry, so he just sat there with his textbook and a half-filled scroll and stared at the other tables.
The library was a gathering place for people from the upper years, the ones who actually needed to be there to pass their subjects. There was a cluster of nearly-adult Slytherins in an appropriately dark corner, small groups of Hufflepuffs of all ages scattered about, and a table nearby full of fourth-year Ravenclaws sharing a stack of books that was almost as tall as Harry.
At the end of that table sat Fiona Murphy and Will Sidwell, and between the thick folds of their robes hanging down around them, Harry could see that their hands were firmly entwined, each squeezing the other gently from time to time. Students joining the group late, having to find space to squeeze in another chair, would sooner enlarge the table than get between them.
And so Harry learned how it was okay to show affection.
"They're so soft," Parvati said, her head bent close to Lavender's near the fire, whispering back and forth. Harry sat behind them and felt invisible.
"As soft as they look?" said Lavender, touching her own lower lip with her fingertips. "He has the best lips in the whole school."
"Except for Davie Wadlow," said Parvati with a flick of her hair, "and he's in seventh year so he'll be gone soon anyway."
"So did you really--?"
"In the nook by the charms classroom," she said. "He was showing me an obfuscation charm and then he said no one could see us for the next two minutes and then he..." And she made a smacking sound with her lips and smiled.
"Right there?" said Lavender excitedly. "Did he, you know, use his tongue?"
Parvati shook her head. "No," she admitted. "But next time, next time I bet he will." And she closed her eyes dreamily and sighed. Lavender giggled and nodded her head and said how she couldn't wait till she got her first.
And so Harry learned how it was okay to kiss.
"It was brilliant," said Seamus, sitting on the edge of his bed, his legs spread wide as though trying to accommodate something well-hidden in his trousers. All four of his dorm-mates were there, crowded onto Dean's bed to face Seamus and hanging on his every word. "It was better than you can even imagine."
"I can't believe you got a sixth year girl to go out with you," said Dean, for the third time in five minutes. "You didn't give her a potion or anything, did you? You're not going to get into trouble for this, are you?"
"Of course not!" said Seamus, and Harry believed it even if Dean didn't. Seamus could never have made that kind of potion, not without blowing something up. "She just likes me, is all."
"Dean, shut up!" said Ron urgently, sitting so far over the edge of the bed Harry couldn't believe he wasn't falling off. "Go on, Seamus, tell us what happened."
Seamus looked quite pleased to be continuing his story. "Well, after I got her under the stands," he said, rubbing the palms of his hangs against the insides of his thighs briskly for a moment, "she opened her robes and let me get, you know, up under her shirt." And he demonstrated with his hands and thin air.
"Whoa," said Ron. "And then?"
"And then what?" said Seamus. "I got to touch her... you know." He held his hands out in front of his chest in a gross exaggeration of Grace O'Doyle's assets.
"I just thought maybe you did more," he said, sighing dramatically as though actually disappointed by that.
"Well, I had to leave something for the second date, after all," said Seamus smugly.
And so Harry learned how it was okay to touch someone else.
Harry never got enough time with his godfather, but he took what he could get and grabbed hold of it with both hands and hung on. He had a whole day ahead of him where he had nothing to do, no demands on him, so he woke up early and bounded down the hallway and pushed his godfather's door open.
He couldn't tell who was with him at first, splayed across the bed, kissing him softly. But the blankets didn't cover much and it took Harry the space of just two kisses to realise that it was his former professor in Sirius's bed. They'd always been friends, he knew; he hadn't imagined that Remus and Sirius were something more.
Neither of them looked towards the door, murmuring softly to each other and kissing every time they stopped to take a breath. He'd never seen Sirius smile like that before, never seen Remus look so relaxed. Their legs tangled and untangled again and all but shoved the covers off and they neither noticed nor cared.
Harry didn't watch them move together for long, creeping back out of the room and closing the door behind him. He wasn't the only one, it looked like, who was grabbing every spare moment he could.
And so Harry learned how it was okay to do those things with other boys.
So when Harry tugged Ron into an empty bedroom in the house at Grimmauld Place, and held his hands and kissed him and rubbed naked against him on the musty bed, he knew it was all okay.