A sister's curiosity leads her to her stepfather's hidden porn stash. As she sifts through the videos, she finds one where a woman is getting fucked roughly from behind. Inspired, she seeks out her stepfather and demands he "comer tras" (fuck her from behind). He initially hesitates, but her persistence and the sight of her bent over, ass ready, prove too much. He slams into her, fucking her hard and deep, just like in the video. Their bodies crash together, his hands gripping her hips tightly, as they both lose themselves in the intense, forceful fucking.