Jessica Simpson remained on tour in Florida last weekend with acoustic style singer John Mayer.

Jessica was spotted at John’s concert at the University of Miami’s Bank United Center-dancing during John’s entire set.

“She was rocking out the whole time,” says one crowd snitch. “She only seemed to know the words to his older songs though, because she sang along to ‘Your Body is a Wonderland’ and his older hits.”

“She was dancing like she was a real fan, and a lot of the crowd had their eyes on her the whole time,” a concertgoer tells PEOPLE.