Watch Olivia Rodrigo and Avril Lavigne’s Surprise Performance of ‘Complicated’ On Sour Tour

teen bop “Complicated,” a song that's as fun to wail along to now as it was when it was released. Fans at the event and online were wildly enthusiastic about the unexpected collab, and posted clips all over Twitter and TikTok.

Lavigne posted some photos and video clips of the moment on Instagram as well, captioning the images with, “Jumped up to sing “Complicated’ on stage with @oliviarodrigo in Toronto tonight. It was very sweet to perform with you tonight on your SOUR tour!! Have an incredible tour gurl. Keep killing it. Sending you so much love.”

Both gals were in prime Y2K fashion, wearing chunky black boots, Lavigne's slouching around her ankles and Rodrigo's laced up tight to her knees. They also had matching short plaid skirts, Rodrigo in blue and Lavigne in red, and Lavigne was wearing a black leather jacket on top. Rodrigo had on a crop top with a heart shaped appliqué across the front, fishnet stockings and lace fingerless gloves. They both let their extravagantly long hair hang loose, the better for throwing around while performing.

Rodrigo has covered “Complicated” on her own before, and told People that she was a “massive fan” of Lavigne. When she was awarded the Songwriter of the Year at the Variety Hitmakers Brunch in December 2021, Lavigne was the person who handed off the award, so the regard seems to be mutual.

Rodrigo's tour will continue, though not much can top this Toronto stop. Despite her traveling and hectic work schedule, the young star has made time for some new romance. Sources have told E! News that she is casually dating DJ Zack Bia, and was photographed with the 25-year-old earlier this week.

“He invited her to Super Bowl parties that he was DJing that weekend and she went to support him,” the source said. “They hit it off and have been casually hanging out.”