One afternoon I went to train at the gym, while there a boy approached me to give me some training instructions (he was the gym instructor), I could see that he was looking at my bulge, since I was in shorts. When I finished my training I went to the shower and we met again, we had a conversation and we began to undress, looking at his huge muscular body and his big ass my cock hardened. After groping each other we went home and I ended up giving him a good fuck until his ass was filled with cum.