I can't answer for other males, but I am not secretly gay and afraid to admit it. I've been married for 19+ years, quite happily so. That doesn't change my experiences before marriage, nor my desires. I'm bisexual, though I usually find women more attractive than men.
I've been told that since I'm monogamous I can't call myself bisexual. To me, that's nonsense. Sexual orientation is not the same as sexual interaction.