This is beautiful! I love the comfort they are able to give each other, the role of educator (educatress? *g* Not a word, I don't think, but it feels right for this) Rosie played in Snape's sexual life, and the way he returns to her whenever he needs that comfort. Love her unashamed approach to sex, too, and her implicit understanding of what is going on in Severus' head. Lovely story.