The Quigleys and the Drysdales are caught in an eternal quadrangle. When Clive and Sonia discover that their respective partners are having an affair, they realize that they are reduced to being the other half of an unpleasant equation. Unwillingly, they join forces in an attempt to save their marriages.

Clive and Sonia join forces as their respective partners continue their clandestine romance. But is Melissa allergic to adultery?

Not only have Vera the cleaner's legs turned blue but Clive's mother is planning to die at ten o'clock.

Who is that following Dave? Why does everybody keep running into Chuck Purvis, private detective?

Dave wants Melissa, but keeps Karen for emergencies.

Clive puts his foot down, gets kissed and likes it. Could there be life after Melissa?