Passion in Hot Hollows (1969)

Cruel, conniving Norma Sue returns to her backwoods hometown with her stud lover to wreak havoc on the local denizens. Her main target is her sexually repressed sister, who runs the local hotel. At the same time, jobless slacker Billy Joe commences an affair with a broke immigrant lady whose husband is overseas. Pressured by his cheating wife to earn some cash, he decides to pimp his new paramour. Norma Sue's scheming eventually involves all these characters in intense, often nasty, interlocking liaisons, betrayals, seductions and violations