I have this on-again, off-again pain in my left testicle. Here's what I notice. It occurs generally if I am stimulated but I do not resolve the stimulation and if I wear certain kinds of underwear or sports wear. I have a pair of Jockey pouch boxer briefs and a pair of a new style of underwear that is a square cut spandex kind of brief--both seem to help create the pain. So, too, do my tri shorts (I am a triathlete.). Bikini briefs don't seem to create the pain. Obviously, I can just not wear these things, stick to the bikini briefs and jocks. But this is strange in my opinion. I wonder if I have some kind of infection that just doesn't want go away and these styles of underwear and the unresolved stimulation (this really gets on my nerves) just irritates the infection. I don't know. But it gets on my nerves. I have had a vasectomy and wonder if that might play a role. Any thoughts? The pain is certainly not intense, but my balls do become tender.