Ashlee Simpson completely shocked fans by joining Demi Lovato on stage on the ‘Holy Fvck’ tour. Watch their epic performance to ‘La La’ here!

Bow down to queen Ashlee Simpson! The 37-year-old singer made a surprise appearance at Demi Lovato‘s concert at the YouTube Theatre in Inglewood, California on Wednesday night (September 28). Demi, 30, brought Ashlee out on stage and they performed Ashlee’s iconic 2004 hit, “La La,” which made the crowd at the Holy Fvck tour go absolutely wild.

“Please give it up for Ashlee Simpson,” Demi announced through the microphone, which received loud cheers and screams from the audience.

Ashlee suddenly rushed onto the stage and started performing “La La” with Demi. Both superstars were dressed in black, with Ashlee’s look including a black jacket and a pair of grey trousers.