I'm straight and am dating a bi guy who has given me some hope and joy in recent months, but that has nothing to do with his sexuality because he just so happens to be bi. His sexual background doesn't bother me since I trust his word that he
is clean, and I'm of that age group where I was inevitably going to be dating a guy who's expected to have
some kind of experience by his 30s (whether a divorcée/widower or who's had at least one previous relationship). Bisexuality's not something I thought about before going out with him, but I do understand the hesitation someone might have after hearing a lot of stories about promiscuity that's prevalent in LGBT circles.
But it's the same with heterosexuals, too. Replace "bisexual" with "playboy" or "whore/slut" and you'll have more polarizing but straightforward answers. In general, it appears majority consensus is the more sexual partners one has had, the harder it is to be in a fully-committed trustworthy relationship because the person who's known to have slept around could return to old habits/have an incurable STD yet still desires companionship, or the person dating them may not 100% trust them to be faithful but never voices their concern. Hence why communication is important, but so is self-control and self-respect, and proving one's own self-worth that they'll never go back on their word.
Also do you think it’s an act of bigotry to discriminate against bisexuals in dating?
Preference/skepticism isn't discrimination when you're concerned about STDs or don't believe that person to be trustworthy. It's based on individualism, not everyone who identifies with the LGBT fucks everything that moves, even though it
does feel like you caught a unicorn finding someone from that camp who believes in being monogamous.
Refusing to date someone because they're "defiled" by the opposite/same gender (militant lesbians hate bi women because they may have been with a man) is a stupid reason, if you ask me. People are more than their sexual labels, but sexual behavior
is cause for concern in terms of personal safety. However, it still comes back to trust, and mutual understanding on those judgment calls.