Katy Perry had a couple of messages for ex-husband Russell Brand at last night’s Billboard Music Awards. First she isn’t dating anyone. She took her grandmother. Second, she sang a big F-U song about their divorce.

Perry, 27, looked like a princess dressed in a long lavender gown with a flowing chiffon looking skirt and what looked like an armor plated bodice.

Her hair was jet black and she wore shocking red lipstick on the red carpet. But her real eye-catching moment was her performance of her new single, “Wide Awake.” It was a high-wire act from start to finish.

The song is from her new 3-D movie/documentary “Katy Perry: Part of Me.” The song was a lament about making herself vulnerable and having her heart broken. Check out the lyrics:

“I’m wide awake. I was in the dark,
I was falling hard with an open heart.
How did I read the stars so wrong.
I was dreaming for so long.
I wish I knew then what I know now.
I wouldn’t dive in,
I wouldn’t bow down.”

The song has a brighter ending, however. Katy also sings about getting back on her feet, picking up the pieces and moving on after her ordeal.

In real life, however, Perry seems to be getting the last laugh. She recently appeared in the arms of Florence + the Machine guitarist Robert Ackroyd at the Coachella Music Festival. Although he wasn’t her date at the show, which says something.

Meanwhile, Brand has been expressing remorse for making a hasty decision to divorce Perry after just 14 months of marriage. He told Ellen DeGeneres he still loved her.

He gets no mercy in Perry’s song; give it a listen below.