There is just so much I love about this story. The slow accumulation of moments and understanding that leads to Harry's realisation and then his offer to Snape. OMG, the gorgeous, gorgeous Shibari binding that Harry performs on Snape.
Their trust, Harry's faith in himself, Snape's ability to relax into the moment when he's in Harry's hands -- so very wonderful. I know I'll be rereading this story.