Mariah Carey and Nick Cannon's divorce is reportedly ''a done deal''.

The couple are believed to have been living separately in New York City since May and their lawyers are said to be in talks about a custody agreement for their four-year-old twins Moroccan and Monroe, as well as a property settlement, according to TMZ.

Sources told the gossip website that cracks started to appear in the pair's relationship when the 'America's Got Talent' host revealed that he'd previously slept with five famous women including Kim Kardashian during an appearance on a US radio show in March, and in a subsequent interview admitted Mariah wouldn't sleep with him until they married.

The revelations is said to have devastated the 44-year-old singer - who married Nick in April 2008 on her private estate in The Bahamas - and left her feeling ''humiliated''.

The 'Hero' hitmaker is also said to be ''angry'' because Nick has taken on so many jobs, but her fury has left the US producer ''incredulous'' after he claimed to have generated $75 million for their family since 2011.

Nick is said to have been living in hotels of late after several disputes between the pair.

A source recently said: ''He hasn't been staying at their home. He's been living out of hotels. They're fighting a lot.''

What's more, rumours of the couple's reported problems were fuelled when they put their mansion up for sale in July, and they haven't been pictured together for months.