Freddie Francis - Mumsy, Nanny, Sonny and Girly AKA Girly (1970)

Synopsis:
Sexy, teenaged, immature Girly and her camera-wielding brother Sonny bring home unsuspecting men to Mumsy and Nanny, where they play games, and if they don’t follow the rules, they’re sent to the angels. One day they bring home a New Friend who has a few ideas for games of his own, though, and he begins to turn the foursome against each other.