THE LOVER by Harold Pinter
Pinter leads the audience to believe that there are three characters in the play: the wife, the husband and the lover. But the lover who comes to call in the afternoons is revealed to be the husband adopting a role. He plays the lover for her: she plays the whore for him. The play contrasts bourgeois domesticity with sexual yearning.
As the play goes on the man (first as the lover and then as the husband) expresses a wish to stop the pretend adultery, to the dismay of the woman. Finally, the husband suddenly switched back to the role of the lover.