Katharine McPhee reportedly stopped talking to "virtually her entire group of friends" after she starred on 'American Idol'.
The 33-year-old actress finished as the runner-up on the fifth season of the show back in 2006 and according to someone close to the situation, her success led Katharine to distance herself from her long-time friends.
The insider told the New York Post newspaper's Page Six column: "After 'Idol', when she got pretty big, Kat just stopped talking to virtually her entire group of friends.
"A whole group went from being best friends with Kat to her not even speaking to them. She stopped responding to texts, calls, everything. Her former best friends are basically strangers to her now."
Katharine married her former manager Nick Cokas, who is 19 years her senior, in 2008 - but the duo divorced last year.
Currently, the American actress is dating music producer David Foster, who is also the ex-husband of reality TV star Yolanda Hadid.
The high-profile couple were first seen together on a date in May and during a previous interview, Katharine revealed they'd known each other for years before their relationship became romantic.
She shared: "We're very close friends, and we've been friends for a long time.
"I'm really, really fond of him, and I think he's an incredible person. I've known him since I was 21 years old, you know? He produced my first single. So he's been really good to me. People can say whatever they want."
In fact, an unnamed source has also insisted that their romance is entirely authentic, rather than something merely designed to increase her profile.
The insider explained: "She's been unlucky in love in the past but she doesn't do anything for publicity. She is a very private person."
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