I've had the pleasure of meeting Jim/hwynym in person. He's a great guy and has helped me out a lot. After he divorced his wife, he actually dated a woman (which was kinda shocking to his ex-wife).

"That's an old fallacy about bisexuals... monogamy can't work with them. It really doesn't make any sense. OK, so they're attracted to both men and women... so what? If you're not bisexual, you may also be attracted to many people who are not your spouse; they just all happen to be the same sex, that's all. If you can maintain a monogamous relationship, a bisexual man should be able to as well. It's no better, and no worse."

Great explanation...I couldn't have said it better myself.