A muscular, tattooed top stands over his sub, a eager smile on his face. He winds up, his fist ready. The sub, balls out, shivers in anticipation. "Punch my balls, sir," he begs, eyes locked onto his master's fist. The first strike lands, a resounding smack that makes both men groan. The sub's balls turn a delicious shade of red, his cock twitching at the intense sensation. Master continues, each punch a test of the sub's endurance, a symphony of pleasure in pain.