Well ladies, I know I am blowing my cover of childhood innocence, that everyone thinks of me, by entering this topic, but there is a small error I need of you ladies to correct.
The famous belief that brief underwear causes infertility is a VERY common misconception in medicine. They do not. In fact it is a theory that started in existence with the invention of briefs in the 1930s, but at that time there were still many doctors who believed that you could predict someone's personality by the bumps in his head.
The other common misconception about both mens briefs and women's panties is that it creates a breeding ground for bacteria and such. This argument is usually based in the idea of a hot place (made hot by the corporal heat) added to other factors like sweat and other corporal things, which I will not mention due to obvious reasons, create a breeding ground for bacteria.
Of course the argument that bebunks it, among others is this: Doesn't the person ever take a shower? Most people take a shower twice a day, and almost everyone takes a good shower at least once a day. Added to other very obvious and basic rules of hygiene like not wearing dirty underwear (duh!) then its virtually impossible for such a thing to happen. If the person isn't very hygienic, then I would worry about that. And in such a case I would suggest him to take a shower instead of wearing boxers.
Well, have I cleared anything up for you people? Or have I just made things more confusing? Now, in case you people are wondering how on earth is a 14 year is knowing so much about this and my answer is: Me and Vicky read and get informed on far too many things not considered appropiate by the adult establishment