Bound and at her mercy, he knows what's coming. She teases him first, running her fingers along his inner thighs, tracing the outline of his balls. He's already hard, anticipating the sweet agony. She smiles, relishing the power. Slowly, she brings her heel down, applying just the right amount of pressure. He groans, a mix of pain and ecstasy. She lifts her foot, letting him catch his breath, before bringing it down again, harder this time. His cock throbs, leaking pre-cum. She laughs, delighted, and continues her relentless ball-busting.