Well... Not exactly. Bi-sexual really means flip-flopping (can't find another word) between both sexes. I have a bunch of female friends who have hooked up or even slept with a woman once or twice, but they really prefer men. Most of the hook ups happen in parties...
Little story: I was walking in Paris with a friend of mine (who is absolutely gorgeous) and I knew that she had hooked up with some girls that I also knew before... And so we were walking, and I mentioned the episodes of her hooking up (we were reminiscing the times lol) and then I said "Well then why don't you go up to that girl and chat her up and get her number for the party tonight" and she replied "I know that I've hooked up with women, but that doesn't mean that I'm gonna go pick one up. I want a man, but if at some party, things go wild again, I can hook up with one but that's not necessarily my goal".
It's kinda like a guy wanting to hook up with a guy just to see how it is... Although it's more pronounced with guys, so it's another thing lol