Christie Brinkley may be one of Billy Joel's several ex-wives, but she is his only "Uptown Girl."

The supermodel, 70, was spotted at Joel's concert in New York City on Friday. In video obtained by Fox News Digital, Brinkley looked elated as she swayed back and forth to "Uptown Girl," a song Joel wrote about her in 1983. She was broadcast on the jumbotron for the whole crowd to see.

Another angle of the moment, captured and shared on TikTok, shows Brinkley singing along.

CHRISTIE BRINKLEY 'OPEN' TO FINDING LOVE BUT LAMENTS LACK OF OPTIONS: 'DOESN'T SEEM TO BE ANYBODY OUT THERE'

Pictures show Joel seemingly singing passionately to Brinkley. 

WATCH: BILLY JOEL SERENADES CHRISTIE BRINKLEY WITH ‘UPTOWN GIRL’

Although the couple divorced in 1994, the two have remained friends. They share a daughter, Alexa Ray Joel, who also performed on Friday at Joel's concert. 

The "Piano Man" singer is finishing up his residency at Madison Square Garden, which began in Jan. 2014 and will end in July 2024.

In 2010, Joel finally confirmed that "Uptown Girl" was written about Brinkley (she did appear in the music video), although he explained that there was more to the story. 

"I wasn't even dating Christie when I started writing the song, I was dating Elle [Macpherson]," Joel shared on "The Howard Stern Show." He remembered a moment when he was surrounded by Brinkley, Macpherson and Whitney Houston while he was working on the song. 

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"That's why I started writing a song called ‘Uptown Girls’. It was plural. I couldn't believe, you know, the situation I was in," he said of having a bevy of beauties near him.

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Joel, 74, said when he and Macpherson went their separate ways, the nature of the song changed because of his relationship with Brinkley. "And then I started dating Christie and rather than it [being] about all these different girls, she became the ‘Uptown Girl.’ I started writing it about one person."

Both the model and musician have since moved on, having each been married four times. In 1994, Brinkley was briefly married to Richard Taubman. She was married to Peter Cook from 1996 to 2008. They have two children together.

Joel married Katie Lee in 2004, only to split in 2009. He is now married to Alexis Roderick. The couple has two daughters.