Niall Horan and Shawn Mendes Teamed Up For a Backstage Rendition of "Mercy"

By Maggie Panos

While Shawn Mendes made us swoon from the American Music Awards stage and Niall Horan took our breath away (without the help of his One Direction bros), the two teamed up for an even sweeter moment that we didn't get to see. Horan provided backup vocals for Mendes (who was also on guitar) for a rendition of "Mercy," off the latter's Illuminate album. Be still our beating hearts!