Butterflies (1978)

Season 2: Episode 6

Susanna, a woman the Parkinsons met on holiday,comes to stay and Ria collects her at the station. On the way home Ria goes into a shop and Leonard,seeing the car,comes over. He meets Susanna. Back home all the menfolk dance attendance on Susanna,who loves the attention. Ria hates her. Leonard phones and suggests he takes Ria for a weekend in Birmingham but she declines,suggesting he takes Susanna instead - which he does.