I've noticed when I get highly sexually aroused, my fingers get numb, and so do my lips. Is this normal?

1) It seems that I can't maintain an erection for more than a couple of minutes during intercourse. In fact, sometimes it doesn't seem to want to get up and play at all. The girlfriend is really starting to take this personally, but I know it's not her fault. Help! Are there any vitamins, diets, etc. that may help?

2) To put it very simply, I am having trouble having erections for a while now. I used to be able to. I can't have them at all, during intimate encounters or during masturbation. I get a little "hard" but cannot get completely hard. Could you please help me? Thank you!!

My roommate and I were wondering whether or not there was a difference in sleeping with a man with an uncircumcised penis or one that has been cut? My roommate's current boyfriend is uncircumcised and she has heard horror stories about sleeping with men that have uncircumcised penises.

My friend had to have both of his testicles removed because of Testicular Torsion... will he be able to get an erection now?? What are the testicles for, anyway??

Is it possible to have too much sex? I didn't see any content on nymphomania. Could you please explain it? Is it considered a disease or something? I'm beginning to think it's a bad thing having too much sex, but it's difficult to consider giving it up; just a mini vacation seems forever and this is for both of us!