Derek Hough in Demand! Inside His 'DWTS' Rehearsal with Bethany Mota

Derek Hough is arguably one of the biggest names on Dancing With The Stars and his life has changed immensely since joining the show 13 seasons ago. The dancing pro has his eyes on another mirror ball trophy this time with YouTube sensation Bethany Moto. The pair invited ET as they rehearse for Monday night's big premiere.

"A typical rehearsal is like four hours," Bethany tells us with a laugh. Derek adds, "It's funny, I've never taken naps during rehearsal ever but for some reason these past couple weeks we've been really tired."

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It's no surprise that Hough is exhausted these days- the dancer/choreographer is in huge demand! In addition to his Dancing gig, Hough will guest star this season on ABC's Nashville.

"Doing a whole routine in an hour, I'm used to that. Learning a bunch of lines, it's a different part of your brain," he admits.

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His partner Bethany is busy building her own empire! With over 7 million YouTube subscribers, her followers will no doubt be flocking to support the dancing couple.

But let's not forgot that Derek himself has won five mirror ball trophies on DWTS, an Emmy for Outstanding Choreography, plus he sings and acts. He's a jack of all trades and his fans will certainly have a hand in getting Derek and Bethany through the competition as well. Clearly, these two make for a dynamic duo.

Watch the video for more behind the scenes of their rehearsal. To see who their competing against watch the clip below.

Dancing With The Stars premieres September 15.