WATCH: Camila Cabello & Shawn Mendes Perform 'I Know What You Did Last Summer'

Camila Cabello and Shawn Mendes are bringing it! 

The two recently performed their amazing duet "I Know What You Did Last Summer" for the first time live on Live with Kelly & Michael.

Cabello and Mendes revealed they actually wrote the song backstage at a Taylor Swift concert. 

“We were just backstage. There were like 100 people in my dressing room at the time, and it was madness back there, but I had this guitar and I was just jamming out, and we basically wrote a pre-chorus and a chorus in like 30 minutes,” Mendes said.

The youngsters have yet to publicly admit they are in a relatioship but they have admitted to having some soft of chemistry. 

“I love storytelling in song writing, and Shawn and I have awesome creative chemistry, so this project was so exciting,” Cabello said. 

RELATED: Watch Camila Cabello Put Those Shawn Mendes Dating Rumors to Rest

Watch the beautiful performance in the video above!