Ok,so for sure he has a fetish for men that dress as women,but you don't know for sure if he has ever acted on it or just masturbates to it. He most likely has had the fetish for years if he's 42. He probably loves you but he also loves his fetish. It's most likely a huge part of his sexuality,thinks about it often. You should talk to him about it although he may not tell you the truth. I know about fetishes (not his fetish though) and I know about not being honest about it and getting married. Better to get it out in the open and make a clear decision.