Somehow he is blindsided by the fact that there is trust between them now. That the Detective seeks him out so easily; that her smiles are becoming softer in his presence. That her touches are warm and comforting, and remind him so much of heaven he almost cries.
And he still wants her. How can he not, when she is the most beautiful and interesting human being since the beginning? But he knows that won't be enough anymore.
Because no hungry kiss can replace the warmth of her gentle touch against his arm. Or their weird inside jokes, that always have her rolling her eyes. Sex can't replace the quiet moments, when she pops over the penthouse with cheap take-out just to talk.
And he wants her like his next breath, but he rather suffocates than lose what they already have.
So when she appears again one night, desperate and hurt, trying to take him on his couch he says no.
Oh, he is willing to be anyone's break-up laid, and he is master of taking their mind off the pain, but he can't do this. He can't take less than everything from the Detective and that's so much more than she is ready to give. He won't violate her trust like that.
So he tells her no, and tucks her in, and tries very hard to forget how divine she looked against his sheets.