As if Clive doesn't have enough troubles being roped in by Sonia to try to scupper his wife's love affair, enter Lester Whales - the exterminator.
As a result of her affair with Dave, Melissa takes up singing to express her newfound passion - so her husband Clive counters by buying a banjo. While the adulterous couple is being followed by Purvis, the private investigator hired by Sonia, Clive himself is being followed by Lester Whales, the jealous husband of his secretary.
To prevent the tipsy Clive from spilling the beans, Sonia whips him off to a hotel where she finds her problems are only just beginning.
Purvis is following Melissa and Lester is following Clive. Sonia and Clive are following Dave and Melissa and then Clive hits the jackpot unexpectedly.
All roads lead to Sonia's country cottage but Dave and Melissa's car breaks down en route, due to a bit of petrol-tank sabotage courtesy of Clive and Sonia. The latter couple do make it to the cottage only to discover another pair making full use of the facilities.
Sonia and Clive are caught by the police lurking with intent in the undergrowth of Sonia's garden. Meanwhile, their respective partners, Melissa and Dave, find that their prospective tryst in a country love nest is well and truly spiked.