1. to hit someone in the family jewels (a.k.a. the seat, the junk, the baby maker, the twig and berries)
2. to hit someone in the balls as a form of punishment or torture.
1. When Jim wasn't looking I decided to give him a punch in the seat and he doubled over in pain.
2. The stupid sonofabitch wouldn't tell me where he hid the cash so I had Vinnie and Nunzio hold him down and I had to give him a punch in the seat a few times before he talked.