Four girls are drawing a male erection in todays art class. Their naked man is handcuffed and gagged and the girls gently tease his cock until it is rock hard. They then start drawing and giggle as they bounce the stiffie up and down with their fingers. Every few seconds one of the girls gently caresses the dick so it is in a constant state of arousal. After a while their fondling becomes too much and the guy starts moaning loudly. Tina takes her hand away and the girls watch in amazement as the cock explodes all on its own!