That Old Feeling (1997)

Lilly and Dan are a couple who have been divorced for years. When their daughter Molly gets married, she invites them. At the reception, Lilly and Dan bicker loudly, so Molly asks them to leave. It's while they are alone that their banter turns into passion and they get it on. Later, when Molly should be having her wedding night, she discovers her parents together and freaks out. The next day they run off and their partners are wondering where they are. Molly decides to try to find them and she enlists a paparazzo who's been following her mother to assist in her search.