Bikini Paradise (1967)

Two U.S. Navy officers, Lt. Fraser and Lt. Crane, are sent to a remote South Pacific island to look for an American teacher, named Miss Harriet Pembroke, whom has gone missing for 20 years. They are captured by eight-woman tribe whom are led by Miss Pembroke herself gone native. When the two men learn they are to used and discarded for marriage and mating purposes, they try to escape with the help from their two sympathetic "wifes" Rachel and Maya.