The pair is performing together at the 2019 GRAMMYs on Sunday, and on the carpet, Mendes played coy with ET on whether he'd be dropping some music with the "Nothing Breaks Like a Heart" singer soon, but given his smile, it wouldn't surprise us!
"I guess we'll just have to just wait and see," the "In My Blood" singer revealed to Apple Music's Zane Lowe, adding when pressed about his smirk, "I never said I had a good poker face."
If we do see a collaboration between the two, it would make sense, given the praise Mendes has for Cyrus as an artist.
"She just lets it all out. She doesn't hold anything back and it's fully music. You can see there's this thing that happens, she starts singing, her eyes just switch over, there's this bliss," he explained. "When you sing with someone who does that, you also fall into it. And it's just a dream to sing with her."
Meanwhile, Cyrus spoke to ET at the MusiCares Person of the Year Celebration honoring Dolly Parton on Friday, where she talked to ET about what her "fairy godmother" country icon has taught her.
Watch the video below for more.