Don’t be fooled by the glitzy costumes and fast footwork of Dancing With The Stars because it looks like there may be a dark side to the hit reality show.

Former contestant and Olympian soccer star, Hope Solo, has a new book out where she makes some serious allegations against her former DWTS partner, Maksim Chmerkovskiy.

In Solo: A Memoir of Hope, the athlete claims that during her season 11 stint on the hit show, Maksim slapped her across the face during training.

"He manhandled me in rehearsals from the start, pushing me, whacking my stomach, bending my arms roughly. I thought that was just how it went — how dancers worked with each other. But it kept getting worse. One day, Maks was trying to put me in a certain position and hit my stomach so hard with his open palm that I had a red handprint there for the rest of the day."

In fear of ending Maksim’s career, Solo decided to continue to train with her allegedly abusive partner.

Maksim, known for his outspoken nature, recently responded with a tweet:

"Always hated hypocrites and liars, but when someone is both and an opportunist, I just feel bad for them. Can't win at someone's expense."