well, i can't speak for everyone else, but in my experiences with anal sex...it is possible for me to orgasm from anal sex alone. i was just talking to a friend about this last night. i have a hard time orgasming just from regular vaginal sex...it usually takes a lot of building up to it and some other form of stimulation as well before i can cum. now i can have clitoral orgasms over and over like nobody's business with no problem! same goes with anal sex. i don't have to have any other kind of stimulation or build up during anal sex in order for me to have an orgasm...and a very powerful orgasm at that. a lot of my most powerful orgasms have come from anal sex.

as for cumming on demand. i'm not quite there yet. i do know it is an achievable thing though because we are at the point now where he can make me cum just from hearing his voice...the things he says...getting me all worked up! god and he knows it too and he likes to drive me crazy with it! lol anyways, so yeah i can cum from hearing his voice...but we aren't at the point yet where he can just up and say the magic words and i start to cum all over the place. maybe eventually ~winks~