Women have admitted to me that bisexuality in men is a major ick. Why?

I am a bisexual man. From my own anecdotal evidence — through things said to me and said to my friends — the women I know (in Australia and the UK) have a preference against dating openly bisexual men. To a greater extent than men I know have a preference against dating openly bisexual women.

Of course, posting this online immediately garners a flood of women saying they love bi guys. That’s great! Please spread the word.

But in the real world, the bias persists. What are the main causes of this? The idea that we’re actually just gay? Fear of STIs? Stronger policing of male sexuality (and if so, why be the cops)?

EDIT: Encourage you to read some of the responses in this thread from 10 years ago. Let’s just say I hope we’ve moved on since then … it’s pretty sickening.