A married woman, under the control of her perverted father-in-law due to his massive dick, submits completely to him despite being a victim of incestuous acts. She forces her younger sister to drink an aphrodisiac and then proceeds to have forbidden threesome sex with her while their father watches and enjoys every moment. The two sisters compete over their father's cock, taking turns sucking and riding it until they reach multiple orgasms. This taboo erotic drama features a super fertile father-in-law who can't get enough of his son's wife and daughter-in-law.