In the last episode of series 5, Frank goes into a coma and dreams of his unusual family, where Monica still has her physical body, but the mental state of Sheila, In which Frank refers to her as Sheila-Monica. This is shown in the way that she dressed and the sound of her voice while holding up a sign of Sheila's face. This may indicate that Frank still has feelings for Sheila, despite their previous marriage being illegal as Frank never got a divorce from Monica before they were to wed.