Wow that's...really hot. And fantastically guilt inducing. That's one of the reasons that I find leaving him at the Dursley's so awful. Dumbledore and co. can just swoop right in, with a little kindness, and he's theirs.
I'm going to pretend that he has Snape wrapped around his finger for the rest of his life, if it's all the same to you. And that he has exactly the kind of children he deserves.