Ground Ball
When a man and a woman decide to have sex and said woman is a v-sit position. The man attempts to screw her while she is sitting. While thrusting, said man's balls come in contact with the floor.
Example:
My girlfriend sat on the floor while I screwed her. My balls uncomfortably scraped against the floor resulting in a ground ball.
My girlfriend sat on the floor while I screwed her. My balls uncomfortably scraped against the floor resulting in a ground ball.