Bad Girls (1981)

Four photo models go on a vacation in the woods in a recreational vehicle. They enjoy themselves in the Rocky Mountains, rowing around the lake, sunbathing, and running around totally naked. They have encounters with a Woodcutter who was having sex with two girls, a Boyscout hitch-hiker, and a not-so-pleased Scoutmaster. Eventually the Scoutmaster will bring the girls to the attention of a secret society who takes them hostage and aim to train them as love slaves. The girls comply up to a point, and escape using their feminine charms on the Scoutmaster to get the keys to freedom.