initial possiblity is maybe ellie goulding creds. it looks like, if you've kept her tour history similar, they toured in 2015 so there could've been something then and now they're thrown back together. or kinda same line of thinking - instead of big musical credits she could've been a backup dancer/band member and/or actually attached to someone else during a past tour (so possibly even an actress) where some entanglement happened and now they're being thrust back together for whatever reason?