Wife Swappers (1965)

Margie, the wife of a young up-and-coming lawyer, reluctantly joins a wife-swapping club and finds that she is to be the hostess for the next party. She complies because of her husband's position but remains on the sidelines at the party and begins to drink while the other women enjoy sex play in the bedrooms and encourage her to join in. Soon, she finds herself the center of attention as she performs a belly dance and striptease. While Margie is dressing in a bedroom, Rudy approaches her and tries to rape her. Margie defends herself with a pair of scissors, and Rudy falls dead on the bed.