David is telling is boxing trainer that he is ready to fight anybody in a boxing match, guys or girls, he doesnt care, he feels like his finger is healed and that he can take on any opponent. His trainer thought he was a little cocky and decided to give him some lowblows (POV, we dont see the lowblows) while David is doing his sparring session. At one point, David took off his gloves to put his hand inside his speedo and move his balls a bit in case his trainer wants to do some more ballbusting (and he did...)