I think bisexuality is more real that homosexuality.. and heterosexuality, for that matter. I see it more of a spectrum of bisexuality... a spectrum of attraction.
Attraction is just a force by which one thing is attracted to another... the way a moth is attracted to light. It doesn't necessarily mean the moth wants to have sex with the light.
And repulsion is a force by which things repel one another
So we all just have a certain level of attraction or repulsion for others. While some may argue that they are repulsed by the same sex, I don't think that is entirely true. You choose your friends by the qualities they have that you are attracted to. That doesn't have to include sexual attraction... but it doesn't have to exclude it either.
So to what degree is that attraction/repulsion?
"Straight" girls may get drunk and make out with other girls. But they have to be attracted enough to that girl (or girls in general) that they feel it is acceptable.
"Gay" boys may get drunk and make out with other girls so they, too, must have a certain level of attraction to them.
I, personally, would never be able to make out with another guy, drunk or not, because my level of attraction for men does not go THAT far.

