Ok... this is akward... For 25 and Older MEN!!!?

I have been engaged for 6 months and with this guy for 2 years. We live together and have for a long ime now. I came home early the other day and he was looking at other men on the internet. He says that it is not that he is gay, just that he finds all kinds of stimulating. Is this a crock of crap or not?