Hi Paula
Your statement reads as "If I'm with a guy I won't touch other guys, but I'm liable to cheat with another women" and visa versa.
I'm thinking that's not how you meant it?
But it comes across that you're untrustworthy.
Who wants to be in a relationship with someone, that is always looking for something better?
Whatever way I go I'm loyal, I hate cheaters as they usually delude themselves into finding reasons why it's ok.
I have little experience with Bisexual people, but if the above was a common trait, it's understandable people would be wary.
I suspect like most things in life it's the bad apples that tar everyone else. That happens in everything, you can't generalise.