Just a Little Harmless Sex (1998)

A strictly monogamous man stops to help a stranded female with a broken down car. In gratitude she offers oral sex, when he reluctantly accepts. However, just as they get involved, the cops arrive and it turns out that the woman is a known prostitute. The man is arrested and is forced to call his wife at 3 AM to bail him out. A few days later he is evicted from his home by his wife. His best friends question how he could have been so naive. Meanwhile his wife and her friends plan their own night out with full sexual plans. Meanwhile the men decide that an apology is at hand. Arriving home, instead of his wife, he finds his mother-in-law. Eventually the guys, girls, and mom all end up together in a night club that brings all the events to a head.