Justin Bieber and Ed Sheeran....Is There A Song In The Works?

The Beibs and Ed Sheeran both took to Instagram to post pictures of themselves standing infront of a green screen then put the two of them together and captioned it "10". Is this some sort of countdown? Do they have a new song, album, tour?!?! TELL US PLEASE! https://www.bbc.co.uk/newsround/48116941