Jem Aswad Senior Music EditorAn apparent collaboration between rapper Young Thug and Nate Ruess, Jack Antonoff’s erstwhile collaborator in the Grammy-winning group Fun., was teased on Instagram by super-producer Jeff Bhasker on Tuesday.The post includes only photos of the two artists and a comment from Bhasker reading “This is happening.”In the photo, Thug is wearing a necklace that reads “Jeffrey,” which refers to his 2016 mixtape of the same name, although perhaps the photo was chosen by