Hi,
just because you and your husband aren't sexual doesn't mean that he's gay. How old is your husband? There are numerous physical and emotional reasons why someone could avoid being sexual. It could be a prostate problem, medications or any other numerous reasons. You need to open the lines of communication and ask him in the most loving way you can -what is his reason for not being sexual. Does he view internet pornography-some men get their gratification from that and stop paying attention to their wives. It could be he's not gay at all and when you accuse him, he just feels like shutting down the communication. Try to be more open minded in the possible reasons for the lack of sexuality. Best of luck to you both.