twosomes... threesomes

Was watching Sex and the City and I was totally intrigued by an episode where Samantha agreed to do a threesome with her boyfriend. Seriously I totally do not get the appeal of threesomes. I mean... in a world where its the survival of the fittest, prettiest, sexiest and most sexually active (...est) why would you invite a rival to get into bed with you?

Yeah I know its like guy's ultimate fantasy to have 2,3 or more girls to service him in bed and honestly there's nothing wrong fantasizing that. What would the world be like if you question a man's fantasy. It's healthy... at least if all else fails it keeps the blood pumping to a man's brains.

But right now I'm just questioning the girls's motive in letting a man do that. As much as a sexual prowess a woman can be there will always be that chance where the guy might just prefer the other women. Now would you woman actually wanna see that? Straight on... in bed... while you're having sex? No way, jose!

If my man ever shows that he prefers another woman while he's in bed with me, I assure you claws will come out. And no... I will not indulge in another of man's fantasy by having a girl-on-girl catfight to see who will have sex with the guy. It's the man that'll have to answer.

Call me old fashioned, conservative, prude or whatever I just don't get the idea of anything more than a twosome. I mean God only made one penis per man and one vagina per woman. Surely that must count for something.