For this scene he kicks back on the couch to watch a bit of porn. There's only one thing guys do when there's porn on, and that's stroke their cock; that's exactly what Josh begins to do. When he hears someone coming, he pulls his pants up and decides to continue his dick teasing in the shower.
Once Josh dries himself off, he decides the best place to get off is on his bed, so he wonders into the bedroom, kicks back and strokes for the home run, which he succeeds in attaining, drenching himself with his jism. It's nap time.
Next Door Male