I have notice that when my gf and I have sex after we are mad at each other is more pleasurable! We have passionate sex ( well, always actually ) but even more when we fight a few minutes before! I guess it is a way to say I am sorry. And its resolved with sex, kisses, hugs, and pleasure! Then at the end after 20 or 50 minutes depending how long we took, we smile at each other hugging and falling asleep. Or go at it again!