I accidentally walked in on my roommate in the shower, his massive cock in hand, stroking it vigorously. His eyes widened in shock, but he didn't stop. I couldn't help but watch as his big dick throbbed, veins pulsating. He turned around, giving me a full view of his ass, and continued to pleasure himself, knowing I was watching. The sight of his thick cock, slick with soap, was too much. I had to leave, but not before he caught me adjusting my hard-on.