Also, a few picograms of endorphins get released into the blood during orgasm. This can have a sedating effect on some people as well. You're probably also experiencing a little guilt. If you answered yes to any of these questions, you are suffering from guilt. If you answered no to any of these questions you are suffering from guilt and denial.
Most people experience a little guilt over indulging in carnal pleasures.
You can't help it after being bombarded by the fucked-up messages we get about sex in this culture. Dennis Franz can hump prostitutes on prime time TV, but you can't sell a condom and heaven forbid Ellen kiss a girl. It can make one feel a little uncertain about the way one is supposed to behave. So you're a modern, 90's kinda guy, who would scoff at Puritans with their backwards notions and funny hats, when all of a sudden that little kid who mocked and ridiculed the idea of masturbation and would have had his lips sewn shut before he French kissed anybody shows up and spoils the afterglow. Rather than be mad at yourself, you project your guilt feelings on your bed mate and act in an insensitive way.