I'm not even in the mood to see what complications this brings to the story. Even if she knows, I doubt she'll say anything, but I'm kind of fed up with the situation as a whole. Also,
@Yabaibunni,that was my first thought too, but upon further reflection, neither of them really care about sex. It's the emotional intimacy and confirmation of attraction that is implied by sex that they want (hence why she's still unfulfilled even though she finally did sleep with her husband, and he wouldn't sleep with his wife when she finally relented and said they could do it). In a few words, lack of sex isn't the problem, just a glaring symptom.