FUSE TV - Shawn Mendes & Fifth Harmony's Camila Cabello Tease New Duet: Watch

They may or may not be dating, but Shawn Mendes and Fifth Harmony's Camila Cabello will go public with what sounds like an extremely promising new duet.

The "Stitches" singer and the girl group member revealed a teaser of their upcoming duet, "I Know What You Did Last Summer," that sees the duo harmonizing over some acoustic guitar strumming. (And by the way, the song has nothing to do with the "I Know What You Did Last Summer," the new duet between Jacob Whitesides and Kelly Rowland).