"Simon and Mezhgan split up in August. He called it off and she wasn't that surprised or even very bothered about it. Mezhgan told her friends she knew it had been coming for a while. She offered him the ring back but he has insisted she keep it," dailymail.co.uk quoted a source as saying.
"As with all his exes, he is being very generous, but he is already dating again and he has been on a dinner date or two with a mystery British brunette," the source said.
Mezhgan, who is a make-up artist, is said to be living in Cowell's $5 million Beverly Hills home after moving out of the house they once shared.
The property is dubbed his "girlfriend graveyard" by friends because it is where his former lover Terri Seymour went after they separated in 2008.
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