Mick Jagger is going to be a great-grandpa.

He may already be, but this is the first one he supposedly knows about.

According to the New York Post, the Rolling Stones frontman's 21-year-old granddaughter, Assisi, is expecting a baby next year with her boyfriend. This may be the beginning of a trend, as Jagger has seven kids by four women.

Assisi is the daughter of 42-year-old Jade Jagger, Mick's daughter with Bianca Jagger.

According to the Post, Jagger, 70, also has a daughter, Karis, 43, with actress Marsha Hunt; children Elizabeth, 29, James, 28, Georgia May, 21, and Gabriel, 16, with model Jerry Hall; and a son, Lucas, 14, with Brazilian TV personality, Luciana Gimenez.

A source told the Daily Mail that Jagger is thrilled.

"He's been joking about becoming a great-great-granddad and still performing,'' the source said.

He probably wasn't joking.

Contact Tony Hicks at Facebook.com/BayAreaNewsGroup.TonyHicks or Twitter.com/insertfoot.