Two girls see how their stepfather fucks their sister.

They were in their room trying to sleep, when they heard some very strange noises, they did not understand what was happening, they came from their mother's room which she shared with her new husband, however those sounds sounded too familiar to them. They were moans that gave away the fact that the couple was fucking hard inside. The strangest thing for them was that their mother was not at home. So who would be with the man, when they peeked out when curiosity got the better of them, they were surprised to see their sister on all fours being penetrated by that man, who claimed to consider himself a father to them.