Flippy Floppy Eh?

Lately, i have been seeing a lot of flip flopping going on in the Gay/Lesbian community. I understand that there are people who are "Bi-Sexual" and for some this is actually sexually appealing.

Is it fair for the people who don't know, or does that make you a little on the down low. If a man Has dated men for years, and no women, then one day he meets a woman he decides he wants to try to be "straight" with. Is that OK for him to do so, and worst is it OK for him not to tell her about his past with other men? Do you think its possible to even be with this woman wholeheartedly?

Are Women just being bisexual out of the curiosity that lies within us all? or are they doing it to impress the men that feel bisexuality is sexy? Is it possible for this girl to have honest wholehearted relationship with a woman? should these people just let people know from jump that curiosity killed the cat, and this may not go beyond sex, so enjoy it while it last?