I have known i was bi since i was a kid. My first sexual experiences, like a lot of people, was same sex masturbation. For much of my life bisexuality in men was quite taboo, and with the AIDS epidemic/scare in the 80s and 90s, well free love was difficult. SO for most of my life i have been functionally straight. BUT during that time i would enjoy gay and bi porn. Then around 2005 i started using Yahoo chat to cam with other men, exploring our fantasies and getting off. When i started playing online i would cam with couples, women and men. While i would still enjoy couples and women i have become pretty much 'cyber-gay', and since i am not having sex at home now, that is my sex life. As an adult i have not had sex with a man, but have jerked myself off with other men who did the same.Its the safest sex. I suspect a lot of men, and women, my age have always been bi, secretly, and as we enter our 'golden years' simply come out in some way. I actually believe most people are, at least sexually, bi. (though romantically they may be straight). Ever notice that all porn has a cum scene, focused on the cock cumming. How many men cum with the guy in the video? If you were totally straight, that scene would do nothing for you! The stigma of being a male bisexual still exists, but i think its silly, because we all look at cock, and enjoy it. I am happy to see these taboos relaxing, finally. I wish i was 20 now, my sexual future would be much more open.
I was the same way. It wasn't until later in life that I discovered an interest in M2M activities. I'm absolutely still interested in women, and still have sex with my wife. But I have had a couple of experiences with other guys, it was very enjoyable, and I look forward to doing it again often. It's not a change in preferences. It's just having fun and experiencing pleasure.