Prone to Temptation (1986)

A tale of two couples trying to come to terms with the hell that's starting to burn between them.

After an exasperating fight with her mother, Debbie decides to leave home and elopes with Boy, the cousin of her boyfriend, Nestor. They get married and stay in the house where Boy and Nestor live, distressing Nestor even more. Debbie’s friend, Letty has been in love with Nestor for a long time and she seizes the opportunity to get closer to him. After a night of sex, they tie the knot and live in a room next to Boy and Debbie’s.