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(Yahoo!) - Don't bother calling Mick Jagger, grandpa!

The 70-year-old rocker's granddaughter, Assisi, 21, confirmed that she is set to give birth to her first child in 2014. According to the first-time mom, the legendary singer is thrilled about the news, so long as you don't call him grandpa.

"He said, 'Well done,'" Assisi shared in an interview with Hello! magazine. "I imagine it's nice to be a great-granddad, although I'm not sure he likes the idea of getting old, or being called one. I call him Mick – I wouldn't start calling him grandpa."

Assisi's mother, designer Jade Jagger, 42, followed up on her daughter's interview telling The Sunday Times that the "Gimme Shelter" singer has always been a family man.

"I think making Mick a grandfather obviously had a big impact whereas, now, making him a great-grandfather is no longer particularly fascinating," she said. "My dad has always been great at keeping the family together and having those important moments – Christmas parties, his birthday. We'll be spending New Year's Eve together, nearly all of us [in Mustique]."

She added that the new family title certainly won't slow her dad down. Mick is currently working on a biopic of singer James Brown.

Congrats on the happy news, Jagger family!

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