Since I was young I've always had a thought that bisexuality is the natural status, but that society's standard of "norms" nudges the majority toward heterosexuality. I had always preferred females, but a hot male body could also make my cock hard as a rock.
After my divorce, I got into the lifestyle. I played with women and couples, but one guy from one of the couples invited me to his place when his wife was at work. The plan was to watch porn and jack off... I sucked my first cock that afternoon.
When I met the woman who would become my second wife and soulmate, I introduced her to the lifestyle. She enjoys men, but she found that she craves pussy. She very quickly and comfortably accepted that she is a bi woman. As we continued to play with couples, we found that most guys are open to some degree of MM interaction. It took me longer to accept my bisexuality than it did for my wife, but our preferred play is primarily bi now. I like pussy and I like cock. My wife spreads her legs for guys to fuck her dripping cunt, but she also loves to bury her face in pussy.
My wife and I are both bi. We feel no need to put limitations on our sexual preferences. Bisexuality just feels natural to us.