[UMD-1010] My sister and her boyfriend stayed at my apartment for a company event in Tokyo, and they had constant sex for three days

Fuck, watching my sister and her boyfriend go at it for two nights straight was the hottest thing I’ve ever seen. They thought I was asleep, but I heard every moan, every slap of skin. The first night, he had her bent over the couch, pounding her pussy from behind while she screamed his name. Her tits were swinging, and I could see her wetness glistening on his cock. The second night, she rode him reverse cowgirl on my bed, her ass bouncing as she took every inch. He grabbed her hips and fucked up into her, making her cum so hard she collapsed. I jerked off to them both nights, imagining it was me inside her. The way she begged for more, the way he filled her up—it was pure depravity. I’ll never forget the sight of her pussy dripping with his cum.