The trouble I see with having casual sex is that the emotional makeup of a woman causes her to become attached once the act has been completed. IMO... men don't tend to react this way. Especially seeing as the woman is in her late twenties! The hormones tend to kick in and the response turns to "MAKE ME PREGNANT"! I honestly don't think it's possible for women to have casual sex... they may say they are into it... but sometimes they go along with it just to "set the hook". If you're not into a relationship than I think you'd be better off with Mrs. Thumb and her four daughters! Having sex with someone changes everything... only a very strong friendship can survive the emotional consequences. Besides, if you really don't care for this person, it won't be a very satisfying experience for you, IMO.

LL