The soloboy, bound by self-imposed discipline, cranks the pump's handle, feeling his balls expand within their tight confines. Each stroke sends a jolt of pleasure-pain through his body, his cock leaking pre-cum in response. The pump's unforgiving grip intensifies the CBT, his balls turning a deep shade of purple, ready to explode. He grits his teeth, teetering on the edge of pleasure and pain, delaying his orgasm as long as he can before finally succumbing to the intense, solo ballbusting session.