Katerina, 34, and Pyotr, 35, siblings by marriage, curl up on the couch for a late-night movie. As the screen flickers, Katerina's eyes glaze over, not with fear, but with desire. She leans in, her hand grazing Pyotr's thigh. He stiffens, but not from fright. She whispers, 'I've always wondered...' Her hand moves to his crotch, feeling his growing hardness. He looks at her, his sister-wife, and gives in. She unzips his pants, taking out his throbbing cock. She licks it, teasingly, before taking it all in. He groans, his hips moving in rhythm with her head. She sucks him off, her hands cupping his balls, until he can't take it anymore. He pulls out, his cock pulsing. She looks up at him, her lips glistening, and he comes, his hot cum spilling onto her belly.