Billy Joel Jokes About Ex-Wife Christie Brinkley's New Romance With John Mellencamp

Midtown complaints about his Uptown Girl. Billy Joel jokingly griped onstage during his Saturday, Sept. 26, show at NYC's Madison Square Garden, about his ex-wife Christie Brinkley dating John Mellencamp.

An observer at the famed venue tells Us Weekly that Joel, 66, made the remark after performing "The Longest Time," one of his anthems about his second wife Brinkley, 61. "And now she's dating John Mellencamp," Joel remarked before the packed crowd.

Billy Joel 

Us Weekly confirmed earlier this month that Brinkley and Mellencamp, 63, were in the beginning stages of a burgeoning romance.

The gorgeous supermodel and the actor were snapped in early September on their first date together.

"They hit it off!" a source close to Brinkley and Mellencamp told Us. "This was only their first date because John was in NYC but so far so good. He obviously thinks she’s gorgeous and she thinks he’s so smart and charismatic."

Christie Brinkley

Family is also a huge factor for both Brinkley and the "Jack and Diane" singer. "They love talking about their kids and being parents," the same insider told Us. "And they both went through divorces so they can bond over that. It’s really sweet and going great so far."

Joel and Brinkley, meanwhile, remain good friends. The exes, who were married from 1985 to 1994, share one daughter, Alexa Ray, 28, and Joel even serenaded Brinkley at MSG last August with his smash hit "Uptown Girl," which featured Brinkley in its 1983 music video.

John Mellencamp

Brinkley subsequently took to Instagram where she reacted to the special song. "It was so sweet to share this moment with my other two kids," wrote the model, who brought her kids Jack and Sailor (whom she shares with her ex-husbands Richard Taubman and Peter Cook, respectively). "They loved it as much as I did."

Mellencamp, meanwhile, dated Meg Ryan for three years before splitting last August. However, he and the actress remain close pals. “I'm very happy with the time I've spent with Meg Ryan," Mellencamp later told the Associated Press. "She's a beautiful girl and I know that I will never, ever, ever be with a funnier girl than her. Not gonna happen. I'm grateful for the three-and-a-half years we've been together.”

Prior to Ryan, Mellencamp was with his third wife, Elaine Irwin -- who also happens to be a stunning model -- from 1992 to 2011. August 2014 was also a big month for Joel and his fourth wife, Alexis, after the two welcomed baby girl Della Rose Joel together.