I think sex and love are separate so you can be bisexual but hetero or homo romantic, only really able to love people of one sex. I think most men are sexually opportunistic, too, like even if it's not their preference they might be able to enjoy something in the moment.

So unless you are some sort of hypocrite who maligns gay men and holds yourself up as some ideal heterosexual while harboring desire for sex with men, there is no problem here, call yourself straight if that's how you identify.