Ma demi-sœur excitée m'a presque surpris en train de me masturber et je l'ai convaincue de baiser

On a weekend at the pool spending time with the family, I decided to masturbate in a slightly remote place, but my stepsister was nearby, and she almost discovered me masturbating, I managed to hide my cock, but because of how horny it was, I managed to convince her to fuck very wild and tough