my ex had the same troubles that youre talking about. he went to a urologist and had an ultrasound and it turned out to be nothing. how old is he? typically once a man hits age 30 he is out of the woods when it comes to things like testicular cancer. the prime age for that is between 15-30 (usually late teens to early 20's). but still go to a doctor just to clear your own mind. and if it is a benign cyst but it is still effecting his ability to maintain an erection, it could be as simple as freezing or cutting it off. (i know it sounds fine to me because i dont have a penis lol)