She's exactly the Scully he remembers, and that means she's perfect - absolutely beautiful, attempting to hold out and then attempting to lose herself in the sensation, and then just riding it out with a little cry. He rides it out with her, and at least this much is true: Even if he's not participating in the ways he'd like to be, he's here with her. He's a part of this, unmistakably, and while it's happening, it's enough.

And after, when she's catching her breath, he wipes off his face and crawls back up beside her. Pulling her in close, he kisses the top of her head; if he knows her (and in the moment, he can truly believe nobody knows her better), she's going to want to curl up with her head on his shoulder.