Common misconception about bisexuals (idea)

Different communities of people tend to have different misconceptions about bisexuals. Even groups of bisexuals have misconceptions about bisexuals.

Some of the misconceptions I've encountered:

• we're all polyamorous
• we'll sleep with anything that moves
• we're more highly evolved (than people who are heterosexual or homosexual, presumably)
• All people are bisexual by nature
• we're all gender-indifferent
• we can't be emotionally fulfilled without at least one lover of each gender
• we're responsible for spreading AIDS to lesbians
• we're responsible for spreading AIDS to heterosexuals
• we're guaranteed to leave our male partners for women
• we're guaranteed to leave our female partners for men
• we're really straight, and sleeping with members of the same sex because it's trendy
• we're really homosexual, and we're only pretending to be attracted to members of the opposite sex in order to cling to heterosexual privilege
• none of us are over the age of thirty

One can, I'm sure, come up with similar lists of misconceptions about heterosexuality and homosexuality. I've probably heard variations on "everyone's really bisexual" most often; however, I hang out with a mostly-bisexual crowd, and that bit of bisupremacy is most often heard from bisexuals, so I can't really generalize from my experience.