Is too much sex in one day bad?

Me and my best friend had sex just a few hours ago, and once we started we really couldn't stop. After I ejaculated, I waited a few minutes and she wanted more. So the cycle kept going for 5 more times. Eventually I denied because my penis was a bit soar. I felt bad, and worried. Is to much sex bad?

I don't think too much sex is bad, but don't do it that much all the time. It's just like don't strain your muscles all the time. It could be bad emotionally, if you fall in love with her and you find out she just wants sex with you (Since you did say she was your "best friend"). Take it easy, if you experience bad symptoms following, see a doctor. It shouldn't be serious though. :)

The problem is defining "too much." It's true that, "man can't live by bread alone," but how much peanut butter is too much depends on the person making the sandwich. :-)