Rent Butterflies: Series 2 (1979)

Ria is a seemingly happily married mother of two teenage sons. Her husband is the lugubrious dentist Ben. His hobby is collecting butterflies, although he seems to spend most of his time arguing with their sons; the thoughtful Russell and the ever cynical Adam. Ria is yearning for a little excitement in her life when she meets Leonard, a handsome businessman. However, her friendship with Leonard seems to be cause of more confusion than pleasure.