Possible Hidden Theme?

During this section of reading Nina asks Alik to get baptized while she is taking care of him. Even though Alik is a jew, he agrees with her on one condition. Nina must call a rabbi too. However by this point of the novel I think that one of the hidden themes in the story emerges here, sex. I do dont believe that the story has to do anything necessarily about sex, but through out the first 6 chapters, there is a lot of uses and reference to seduction and women. When Nina asks Alik to get baptized, she asks him while laying down beside him. I could be wrong, but by this act I believe that Nina is trying to persuade him. Between Alik being surrounded by women, seeing them almost nude, describing how each one is beautiful, and having the vision of the women sitting on the ground, I think its safe to say that women are his weakness. And by that note I think its clear that Nina is trying to take advantage of him.