The lady singer actually takes 3 forms, in front of a mirror- in a white dress, in a red dress and a black dress
The lady in the white dress is holding a ring which her husband presented - and unable to decide whether or not to forgive her husband, who cheated on her . The lady in the black dress has decided not to forgive him, whereas the one in the red dress is feeling sexy, and forgives him. These are basically shades of the same woman, pondering over her husband's infidelity before a mirror.
The husband is shown cheating when he goes through some dark alleys