She can feel it when he mostly forgets about her and falls into his own head, and that's fine. She's come once already and he doesn't strike her as the type to finish and pass out and even if he is, it's not like she can't take care of herself. Plus, it's sexy as all hell to be used sometimes when it doesn't feel exploitative and Diane is keenly aware of who got who into this particular position.

So she urges him on as best she can, cooing in his ear, angling her hips to let him fuck her harder. Faster. Letting him take her the way he wants to.