For Jessica Simpson, supporting Ashlee Simpson has been a public affair.

After all, the “With You” singer shared insight into joining her ex-husband Eric Johnson to cheer on Ashlee as she kicked off her “I Am Me” residency on Aug. 29 at the Venetian Resort Las Vegas.

“We are all a big, happy family, so it’s important for all of us,” Jessica exclusively told E! News on the 2025 MTV Video Music Awards red carpet Sept. 7. “We wouldn’t have missed Ashlee, are you kidding me? It was such a moment.”(See all the stars arriving here.)

As a big sister, the artist reflected on the emotional experience of watching Ashlee alongside their parents Joe Simpson and Tina Ann Drew. She admitted, “I was a mess. I cried probably seven times.” 

Although Jessica—who shares kids Maxwell, 13, Ace, 12, and Birdie, 6, with the NFL alum—has her own impressive music career, she found herself bumping alongside her little sister’s tracks. The 45-year-old teased, “I think I know her lyrics better than my own old songs.”