Lately I've been noticing a strange twitching feeling in my penis when tapping on the back of my right leg with something such as a pen. Also noticed that during sex, often my right foot twitches (especially when focusing around the head of the penis). How is this happening and is this normal? I also have considerable groin discomfort on that side that comes and goes, moreso when running or exerting myself.

Anyone have a clue what's going on?