Guh. That was simply amazing. Beautifully written. Harry was just so broken and Teddy needed him so much, and then; Harry was there. Lovely.
I loved this paragraph:
Eventually, they did seem to fit together effortlessly. By the end of the Christmas holiday, Teddy could throw himself over the side of the bed and let Harry thrust into him with nothing held back. Teddy would grip the sheets and egg him on, and he'd be dizzy by the end of it, his own come spilled down the side of the bed. Harry showed him things he had only heard the vaguest mentions of in the boy's dormitory at school, like the morning he slipped beneath the blankets, pulled Teddy's arse cheeks apart and licked into him until he was bright-cheeked and cursing in blubbered ecstasy. Once, after a bit of post-dinner brandy, he really did put Teddy over his knee and spank him until his cock was hard against Teddy's stomach, and Teddy moaned happily, calling him Father and begging for mercy. They didn't talk about it afterward, but they did it again the next night, sober, Teddy on his knees and holding onto the headboard this time.