It's a common thought that sex is like pizza. Even when it's bad, it's still pretty good. Hell, Domino's managed to spread ketchup on cardboard for years and still turn a profit based on the idea that there really is no such thing as bad pizza, and consequently, no such thing as bad sex.
Sex is like pizza alright--for men.
For women, sex is like prime rib. Everything has to be perfectly timed in the perfect environment. One fuck-up, no matter how seemingly minor, and sex becomes "Fuck it, no, it's gross now. Get it away from me, I don't even want the fucking thing anymore. The whole night is ruined, I'm putting on sweats and grabbing some french fries and eating them alone. Don't come near me."
French fries are masturbation, by the way. You don't always want them, but sometimes they are all that's gonna satisfy that craving.
And no one wants to share.