It may be the middle of winter, but Shawn Mendes and Camila Cabello are heating things up. On Monday night (Jan. 4), the teen duo appeared on The Tonight Show Starring Jimmy Fallon to give yet another dramatic performance of their duet "I Know What You Did Last Summer" with just a little help from The Roots.

The performance, which was backlit by deep blue hues, kicked off with a crack of thunder and lightning, and Cabello and Mendes carried that electricity into their performance. Cabello played up the sexy danger of "IKWYDLS" by stroking her hair and offering up her best mugs for the camera. Meanwhile, Mendes rocked out strumming on his acoustic guitar alongside The Roots.

And even though Cabello and Mendes keep denying all of those dating rumors, their heat in this performance seems undeniable, no matter how cool the lighting or the New York streets outside the studio may be.