I Will, I Will...For Now(1976)

They set out to try everything in the book...what happens next you won't find in any book...

Les Bingham takes umbrage that his ex-wife Katie has a new love in life. What he doesn't know is that her new paramour is lawyer Lou Springer. When Katie's sister Sally arrives and tells the two about her new, hip '70s marriage contract, Les and Katie decide to try to get together again under a more liberal marriage contract, like Katie's sister. But, unfortunately for the couple, the contract is planted with the seeds of self-destruction.