Bound by chastity, he's left alone with his thoughts and his throbbing cock. He's been good, following the rules, but the pressure is too much. He sneaks a hand under his clothes, finding his hard, leaking dick. He strokes it, slowly, torturously, until he can't take it anymore. With a muffled cry, he comes, his cum soaking through his pants, a stark reminder of his forbidden pleasure.