Camila Cabello and Shawn Mendes may not be a couple, but on Nov. 7, the two stars proved they have been working on music together when they released a teaser for their upcoming duet online.

A 15-second teaser was uploaded to Shawn Mendes' YouTube channel. The video, for a song called "I Know What You Did Last Summer," features an acoustic sound and has vocals from both Mendes and Cabello. Visually the video shows Mendes' and Cabello's silhouettes in front of a blue background.

Along with the video, the stars also linked to a website that features television static, the hashtag #ikwydls and the words "coming soon."

The two pop singers have teased possibly working together several times before. They both shared a video on Instagram of an acoustic musical session they had while hanging out together.

The duet would be another collaboration for Mendes, who previously worked with Hailee Steinfeld on an acoustic cover of his song "Stitches," but the first for Cabello.

Working with Mendes would be the 18-year-old Latina's first solo project. Cabello told Latina magazine that the members of Fifth Harmony think its important for each of them to do their own thing.

"We allow one another to do our own thing within this thing," she said. "I think it's healthy because if not, personally, I would go insane."

The singer also discussed the groups future and caused a panic for fans when she revealed that she believed a split was unavoidable.

"Honestly, I think we all do," said the singer.

"We'd be lying if we all said this is a picture-perfect thing, like we all completely agreed on the album track list and what the sound and the music-video treatment would be like, which usually happens in bands who grew up together. But for manufactured bands, it's harder."

However, after the comments, the group made sure to reassure fans that they were not going anywhere by revealing that they were already working on new music.

Check out the video teaser for "I Know What You Did Last Summer" below.