"Crying this was the best moment in my life," tweeted the 13-year-old fan.

If you're casually singing some Ed Sheeran at your local mall, fair warning: Sheeran himself may join you for a rendition of "Thinking Out Loud."

Sheeran recently swung by a mall in Edmonton, Canada, where 13-year-old Sydney Bourbeau was performing at a fundraiser for the Edmonton Humane Society. Midway through the performance, Sheeran rushed the stage (typically super rude, but we're guessing she didn't mind at all) to turn the song into a duet.

Bourbeau deserves major props for not outwardly freaking the heck out during her self-described "best moment in my life," instead calmly finishing out the tune before Sheeran raced off. While she didn't get to talk to him after the impromptu performance, she told the local paper that his team reached out and gave her tickets to an upcoming concert, so the two will be singing together again in the future (albeit this time amid thousands of other people).

https://t.co/ICWWkhl1Zq Crying this was the best moment in my life

— Sydney (@sydneybourbeau) June 14, 2015

This article originally appeared on Billboard.com.