Gunner Mark, home alone, decides to make the most of his solitude. He pulls out his stiffening cock, starting with a slow, teasing stroke. His sister's best friend, visiting unannounced, spots him through the slightly ajar door. Intrigued and aroused, she silently watches him build a steady rhythm, his hand gliding up and down his rigid shaft. His breathing grows heavier, his body language more animated. She can't look away as he brings himself closer and closer to release, his climax a beautiful, messy sight she'll never forget.