This is absolutely gorgeous. I love the rings on Severus' hand and the way his fingers are drawn crooked just so. I love Harry's hair and the way it's long but very masculine. Same with Severus', actually.
And like everyone else, it seems, I love the way you've drawn their chests (yes, the nipples).
This is just the most beautiful thing. I love every single thing about it, from the way you've drawn the characters to the background colors and objects.