Is Madonna nostalgic for the past? Singer posts PDA pic with Sean Penn ahead of birthday

Madonna's birthday is just around the corner, and the pop culture icon is taking a second to reflect on the past.

Before she turns 57 on Sunday, the entertainer posted a throwback photo of Sean Penn -- whose birthday happens to fall one day after Madonna's -- lovingly kissing her cheek.

"Its almost our birthdays!! 2 Leo's ❤️#rebelhearts," the singer captioned the black-and-white pic of the former couple, who married on her 27th birthday in 1985.

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It's a particularly sweet callback to a happier time when the two celebs were together, even though their relationship was rocky at best.

Remember when Madonna dedicated her 1986 album, True Blue, to Penn? In the dedication she wrote, "This is dedicated to my husband, the coolest guy in the universe." The two divorced in 1989.

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See Madonna through the years:

But there's no bad blood here between Madonna and Penn, who turns 55.

"I'm very friendly with my first ex-wife," Penn said in a January interview with Esquire U.K.

Madonna's teenage son Rocco even channeled Penn's character, Jeff Spicoli, from 1982's The Fast Times at Ridgemont High in 2014 which she proudly showed to the world. "Jeff Spicoli is alive and well in the South of France! #boom #fuzzy," she captioned the candid moment.

As we count down the days to the Material Girl's 57th, here's hoping she makes a splash like she did last year!