Awesome perspectives so far gang! Thanks for your replies.
I see how some have considered the withholding to be something to enhance the desire for sex - I am with you on that but I think it should only last a few hours at most. In this case however, it is not intended as a form of fore-play. I believe it to be in the malicious "I am going to punish you" sense.
I totally agree with everyone who remarked that it is a very quick way to kill a relationship. I mean, we are expected to be monogamous (well, most of us anyways

) yet our partner punishes us by refusing sex?! How does that work out?
I also agree that it seems kinda stupid to punish your partner whilst inflicting (one would assume) the same punishment on yourself. This of course assumes that the partner withholding enjoys the sex - if not, then I suppose they really aren't suffering.
Ok .. so I really didn't mean to bias any opinions by spouting my own so I'll leave it at that.
Now let me ask you, my fellow TFPers, what (if any) reaction / reciprocal "declaration of relationship war" would you say matches the withholding of sex?
(I realize that it is childish and serves no helpful purpose to escalate a negative response solely for the purpose of revenge .. but lets just suspend the morality for a moment)