Maks Chmerkovskiy shocked fans by skipping out on his Dancing With The Stars performance last night due to "personal issues" — but Breaking Celebrity News has the true story behind his puzzling absence.

According to a show insider, the pro's celebrity partner Vanessa Lachey, 36, is so "difficult" to work with, the pro refused to dance with her!

"Vanessa is the boss and likes submissive men that do what she tells them to do," a source exclusively told Breaking Celebrity News. "She wants to choreograph her own dances, select her own music and even design her own costumes."

Chmerkovskiy, 37, is so furious with Lachey's belittling behavior, he may never come back to work!

"Vanessa thinks she's the pro and the star and doesn't want a partner – she wants an employee who does what she says," the source added. "Maks is done with her and might not return to the ballroom."

As Breaking Celebrity News told you first, the actress and TV hostess has been a nightmare for the DWTS cast and crew all season.

"Vanessa's ego is just through the roof," an on-set source told Breaking Celebrity News last month. "She acts like she is this huge celebrity, and is really just a big diva!"

Another insider told Breaking Celebrity News she was jealous over her husband and competitor Nick Lachey's close moves with gorgeous partner Peta Murgatroyd, 31.

"Her issues are starting to affect everyone," the insider said. "Everyone is just hoping she gets eliminated soon!"