My wife is intrigued that squeezing my balls makes me really hard. A little while ago she said "I wonder if I could make you cum just by squeezing your balls?". Next time we had sex she tried just that, ignoring my cock completely. At first it was just hard squeezing and releasing in her big strong hands. Then harder and longer. I was gasping with pain and pleasure but she was kissing me and I couldn't speak. Then she squeezed so hard one of my balls popped out from her crushing grip. That really hurt so she did it again and again. Eventually I couldn't take any more and had to pull away and go down on her. Once I'd pleasured her she took hold of my balls again and carried on hurting them but this time she also played with my cock and - in her own time and with me writhing in pain and frustration - finally made me cum.