Quoting from my book Freeing Yourself From the Narcissist in Your Life: "The narcissist puts his life in neat compartment that are separate from one another...These are kept separate from the unconscious parts of himself that feel depressed, enraged, empty and helpless. 

Without a developed conscience the high level continues his acting out patterns. The compartmentalization keeps the ego of the high level narcissist fully inflated. It is smooth sailing for them to act out in duplicitous ways with different partners. 

The renowned painter Pablo Picasso often had affairs with several women going at one time.

High level narcissists never apologize or look back with regret over the psychological and emotional abuse they have instigated. The simply move on to the next man or woman who fulfills their needs for adoration, libidinal excitement, veneration, constant attention.