The Very Friendly Neighbors (1969)

They lived! Side by side!

Lisa, a beautiful Hollywood starlet, grows tired of her playboy husband, Charlie, and attempts to seduce her newlywed neighbor's husband. Lisa settles for a lesbian bout with the wife when her advances are spurned by the husband. Charlie likewise begins to look elsewhere for satisfaction. He goes to Hollywood swim parties with his employer and witnesses him seduce a virgin by hypnosis. Lisa and Charlie decide to engage in group sex with their neighbors, but after a short time the newlyweds' feeling of guilt forces them to withdraw. Lisa and Charlie then engage in mate swapping with Charlie's employer and his new bride, his hypnosis victim. Eventually, Lisa becomes tired of the same sex partners and begins to search for new lovers.