Every girl i know have different preferences concerning what can and cannot be done with their asses. Now, I'm gonna leave any past boyfriends I had out of this...because well it's OBVIOUS they like it up the butt.
Anyhow, Girls range anywhere from liking a quick spank on the ass, to full blown ass worship. HOWEVER, Doing anal itself...not something I've found any girl is willing to do. If a girl DOES let you do it...well...it's because she REALLY loves you and wants you to love her...it's almost a gift really, completely self sacrificing, because I'm willing to bet iyt wasn't their idea. Now, in the same token ladies, understand while the idea makes you cringe, it IS proven to be a semi-enjoyable experience...it's like losing your virginity, but for your ass. There are pleasure centers in a woman's ass that give her pleasure, just not as much as the vagina. We men have a prostate that can be massaged, that's why it feels better for us to have something in there(Oh yes guys, I mean it...you wanna know passion? Next time you and your girlfriend are doing foreplay, tell her to tickle your asshole a bit, you'll like it).