Straight men kiss girls, bisexuals kiss girls, lesbians kiss girls…and apparently so do gay men?

All the lesbians know what I'm talking about…you have that one group of gay guy friends that like to touch on your boobies, or make out with straight girls (or you, 'til you punch them out.)
So why do gay guys enjoy messing around with girls? You and I both know that 90% of lesbians would NEVER mess around with guys just "for fun" right?