Dudley and Muriel play a game of Cluedo to decide who'll do the washing-up, whilst waiting for daughters Jacqui and Susan to return home from an evening out with their respective boyfriends. Meanwhile, Duncan has had a new telephone answering machine installed in his office, and Dudley embarks on a campaign to drive him mad with garbled messages. Susan's beau, Matthew, has just gotten his own flat, and she is contemplating moving in with him. Jacqui introduces her parents to her intellectually superior boyfriend Clive, whom she announces will be moving into the ground floor flat with her as soon as her sister moves out! Duncan calls in an engineer, Arnold, to service his answering machine, and dumb secretary Marlene develops a crush on him; unfortunately for her, he turns out to be gay. Matthew's father, a Church of England vicar, arrives at the Rush house to discuss the infeasibility of mixed flat sharing on church property.