1. Respect other people’s identities. Don’t say that “everyone’s really bisexual.” Don’t say that bisexual people are somehow more evolved. Think of how frustrated you feel when you hear someone tell you that there is no such thing as a bisexual, or that bisexuals are really lesbians or gay men in transition, or that we are really heterosexual tourists out for sexual adventure at the expense of lesbians and gay men.
2. Don’t raise your own self-image at the expense of other people. Examples of bad ideas taken from real life: a t-shirt that says “Monosexuals bore me;” a button that says “Gay is good but bi is best.” Please.
Robyn Ochs, Bisexual Etiquette: Helpful Hints for Bisexuals Working with Lesbians and Gay Men
Seriously, read the whole thing.