Keltham is entertaining Suspicions about how many planes of existence, exactly, just happen to contain women who like totally want you to bite their ears and lips, and will derive their own sexual pleasure from it, instead of disliking pain in accordance with all sane evolutionary logic, and also won't end up actually injured if you do that, and how likely it is that he would end up someplace like that just at random, but he will also worry about that later. If some unknown force throws you into a suspiciously sexually compatible universe, the optimal response should include fucking that universe and not just contemplating how suspiciously sexually compatible it is.
Once they're down the stairs, he'll give Carissa a sudden surprise push, and then be about to leap on her when he remembers the existence of windows and doors that need closing. "Wait here," he says, the words coming out a little more forcefully than they should have, and goes to try to seal the room insofar as that seems to be a thing.