Okay, so my girlfriend came over, and I'm 18 and we started messing around and making out. Anyway we did that, then progressed, and stripped. She was really wet and I was hard but when I put the condom and we started having intercourse I couldn't . I went about 20 minutes and she climaxed but I just couldn't. Why is that? Was the condom too tight? Not lubricated enough? Or what? What kind of condoms should I get.