Take it easy on my heart.
The American Music Awards provided several fantastic televised moments, but a couple of the best happened off screen, and they both involve Niall Horan.
Following his brief run-in with Zayn Malik, Horan swooped by Shawn Mendes's dressing room to sing a bare bones rendition of Mendes' Illuminate single "Mercy," which he also performed at the awards show.
The duet isn't much of a surprise – Mendes recently told Capital FM the two had plans to collaborate together all along.
"I got a chance to speak to him recently and we are definitely going to write together," he said. "We are going into the studio as soon as we can get our diaries together and see what we come up with."