Hilary Duff watches her ex-boyfriend Joel Madden perform with Good Charlotte in Las Vegas as she poses for a selfie with  his wife Nicole Richie

Hilary Duff shared a selfie taken while watching her ex-boyfriend, Joel Madden, perform with Good Charlotte during their performance at When We Were Young in Las Vegas on Monday.

The 36-year-old actress was joined by her good friend Nicole Richie, whose husband is the group’s frontman, as she took the photo.

The Lizzie McGuire star, who recently spent quality time with her youngest child as she stepped out in Los Angeles, wore a beautiful floral print dress as she spent time at the festival.

Duff’s beautiful blonde hair fell to her shoulders and matched the light tone of her clothing.

The artist then shared a photo of Christopher Mintz-Plasse, who she affectionately called “Mintzy,” watching her husband, Matthew Koma, perform as part of her ex-boyfriend’s band.

Duff and Madden, 44, made headlines when it was revealed they started dating in 2004.

The couple received a lot of attention due to their age difference, as the actress was only 16 and the singer was 25 when they began their romance.

The artists remained together until November 2006, when they broke up.

Madden quickly moved on with Richie, 42, who he started dating just a month after breaking up with Duff.

The couple started a family with the birth of their daughter Sparrow, 15, in January 2008, and in September they welcomed a son named Harlow, 14.

The happy couple got engaged in February 2010 and married in December.

Duff eventually married former professional ice hockey player Mike Comrie in 2000, and they welcomed a son named Luca, 11, before divorcing in 2006.

The actress married Koma in 2019 and they share a pair of daughters named Banks, five, and Mae, two.

Good company: The 36-year-old actress was joined by her good friend Nicole Richie, whose husband is the group’s frontman, as she took the photo; Richie can be seen with Madden in 2019

Showing his support: The artist then shared a photo of Christopher Mintz-Plasse, who she affectionately called “Mintzy,” watching her husband, Matthew Koma, perform with Good Charlotte at the festival

Happy couple: The actress married Koma in 2019 and they share a pair of daughters named Banks, five, and Mae, two; they are seen in March

Duff spoke about her friendship with her ex-boyfriend and his wife during an episode of Watch What Happens Live With Andy Cohen that aired last January, and she revealed that the couple had recently become her neighbors.

The Disney Channel alum stated via Entertainment tonight: ‘I have a good relationship with their whole family… we basically hang out all the time.’

The How I Met Your Father star also revealed that she had developed a close friendship with Madden and Richie since moving in next door.

The actress noted, “We let them walk with us all the time. And you know what? It’s beautiful!’