He nods, squeezing her hand back, and leaning in for a soft small kiss.

He does feel safe with her. And he started feeling safe with her must faster than he did with anyone else. Her literally saving his life probably helped with that, but even before then, he was a lot more comfortable than he usually is with someone new.

And part of him does feel relieved he's told her. Mostly because once Sherlock realized, it felt wrong to keep it from Joan. While another part wishes neither of them had ever noticed, so he didn't have to think about it.

And then a tiny part of him is glad that Joan knows him a little better now. That she knows another detail of his history.

"Can we stop talking about it now?" he whispers. He hopes she at least knows that it doesn't change anything about how he feels about her.