I'm going on a date with a girl who I really like, but I don't know whether or not I should tell her that I may be bisexual. What do you guys think?
I'd wait until the second or third date at the least. You surely don't want to start a new relationship off with omitting the truth about who you are. And that way you give the girl a chance to decide for herself if she's okay with dating a bisexual man. I mean, I know there's nothing wrong with it, but you never know where things made lead after just one date. Plus, you might want to make sure this girl is LGBT friendly, good luck!
I wouldn't complicate things too much on a first date. Ultimately, the first date should be about seeing if you actually like eachother in that way. I'd tell her probably 3rd date ish. So you're open, but she knows it won't be a problem because you do like her.