Back in high school, I had an aggressively heterosexual female friend who would kiss women if she was drunk enough.
Like someone once said: "You're not a lesbian if you did it once with your best friend after eight martinis in the Bahamas."
Someone else once said (about men):"You can date a thousand different women and have sex with all of them. But, suck one c**k, and you're just another [fill in whatever derogatory term for a male homosexual is currently in vogue].