I FOUND IT
THE PERFECT METAPHOR!
Heterosexual: I drink Coke
Homosexual: I drink Pepsi
Bisexual: I like both. Not at the same time, but I do like both. Sometimes, I have a preference for one, though.
Polygamist: I mix mine together sometimes. Other times I just have a bunch of cans of one at a time.
Transsexual: I drink my Coke out of a Pepsi glass and vice versa.
Pansexual: It's all just soda to me. I drink whatever I'm in the mood for.
Demisexual: I need to try it again before I make my decision. (I (aka not a demi) made this one, so it might be a little inaccurate)
Asexual: I drink water.
Do you get it now?