What could provoke my husband to "manscape"??

My husband doesn't shave down there...period. He will every blue moon trim a very little bit to keep it from being like too bushy. And me I'm like a hairless cat..except for now. I'm 33 weeks and can't see what I'm doing down there..so I still shave to keep it clean but I'm not hairless. Lol anyways last night he came out of the shower and he flashed me...he had shaved everything. And its not like we have been having the craziest sex life either because sex has decreased quite a bit lately. And its not because I'm not in the mood...its him..he isn't in the mood.and we have kinda been distant this past week or two. He has always refused to shave it off!! And I'm just wondering what provoked him to do it. :/ idk if its crazy to think but could it be a sign of cheating or something?