Papa, the Lil' Boats (1971)

Marc and his gang have a brilliant idea (or so they think!) : they will kidnap Vénus de Palma, a (very) rich heiress. Well Venus, also known as Cookie, is duly abducted but holding the lovely twenty-year-old beauty is a horse of another color. Cookie is indeed both seductive and intelligent and manages to seduce one member of the gang after the other, pitting the ones against the others... The brilliant idea soon proves a nightmare!