Being faithful is no different for bisexuals than it is for anyone else.
I know I wouldn't be happy in a relationship with a man who denied me the pleasure of giving him head. A bi male dating a woman would be faced with the same loss if hemmed in with strict monogamous rules. Is that part of them expected to just wither and die, forgotten?
Gillette, I am struck by your skilled intuition and wisdom once again! This is also at the heart of my recent questioning about my own orientation and ability to follow through. The bisexual "condition" includes an orientation towards both sexes... for some it might just be a mild appreciation, for others a deep hunger.
I think that difficulties with commitment and/or fidelity occur with pretty much the same frequency, regardless of sexual orientation.
I think the ability to commit and/or to be faithful has a lot more to do with an individual's psychology, and the intensity of his or her sex drive, than it has to do with the orientation of his or her sex drive.
HollyBlue then hits the nail on the head... I would have to agree that the intensity of the sex drive is a large factor affecting one's ability to be faithful. I know from experience mine is much stronger than others. I think HollyBlue shows a high sex drive is not seen as an "excuse" but as a plain fact of a person's physiology.
And as others above point towards love being a factor in all of this... there lies the mystery. Conversations about sex drive or the mind's ability to form a committed relationship can not be discussed without including the mysteriousness of the heart's ability to create meaningful change, to deepen once's experience of sexuality and intimacy. I am learning through these conversations here that my desire to understand my own sex drive, my questioning of my own orientation (present or future) is somewhat incomplete if I do not also question my heart's ability to love.