Please Don't Stop (1986)

Petulant Pearl (Amber Lynn) is a gold-digging tramp if there ever was one! While hitchhiking, she meets an unattractive type who's going to visit her rich sister Lynn (Sheri St. Claire) for the first time since childhood. Well, Pearl smells a boner bonus and trades places with her companion. It's going to be a weekend of delicious and hot deception.