Don't Wait Up S04 E01 Episode One

Doctor Tom Latimer splits from his wife Helen. Simultaneously, his father Toby, also a doctor, announces his intention to divorce his wife of 32 years, Angela. Father and son move in together and frequently quarrel about politics and medical practices, Toby being more of a 'Harley Street' type and well to the right of the more liberal Tom. The latter tries to get his parents back together, while beginning a romance with Toby's secretary Madeleine, whom he later marries.