“I love u @shawnmendes thank u for being so there for me yesterday and every other day, u have the most caring and beautiful heart in the world !” she wrote. “Thanks to all our fans for voting , we love and appreciate you guys so much and are so thankful for you ❤️.”
The sweet words were accompanied by a slideshow showing the two all glammed up and enjoying their night out at the awards show, where they performed their collaborative single, "Señorita."
Mendes, 21, and Cabello, 22, also took home the award for Collaboration of the Year for the sexy track.
As well as a clip of their acceptance speech -- during which they adorably gave a shout-out to Mendes’ mom, Karen, for watching the awards show from Toronto, Canada -- the slideshow also featured dreamy black-and-white snaps of the lovebirds behind the scenes.
The couple’s highly anticipated AMA’s performance brought the heat to the Microsoft Theater at L.A. Live in Los Angeles, where the singers teased the crowd by embracing, stroking each other and gazing into each other’s eyes.
The performance came just days after it was announced that “Señorita” is up for a GRAMMY Award for Best Pop Duo/Group Performance.