There isn't an easy way to respond to it; like he says, it's not about her-- so her reaction is going to be secondary. She can try not to make it worse, but she can't do much to truly make things better.

"In fairness, none of this has ever happened before," she points out, shifting so she can look at him, her chin on his shoulder. There's a part of her that wants to pick it apart, to talk about all of it-- not what happened or didn't, but the history behind it-- but she's not ready to get into it. Not in the middle of the night, still thrumming from the feel of his hands on her. The better thing would be to salvage the mood as best they can, and maybe convince him to sleep a little.