because any sort of girl-on-girl is hot, whereas any sort of male-on-male activity is gay. i do find the snowballing thing interesting, though, because it's your own semen. i don't mind kissing my boyfriend after he goes down on me. in fact, i want to: lick and suck on his lips and tongue, taste me on him. i had a boyfriend who would barely even look in my direction after i swallowed his cum, so i was trained for those 5 years to think that it was a huge no-no for all guys. i always brush and mouthwash a few minutes after anyway, to this day. my boyfriend now actually usually will kiss me, close-mouthed, after a blowjob session. that's a big step for straight guys in my book, but just enough of one for me to handle. maybe i'm just a big prude after all.