Kym Johnson and Robert Herjavec may be hooking up when the cameras aren't rolling. Credit: JB Lacroix/WireImage

Dirty dancing? Robert Herjavec may be doing a little more than competing for the Mirrorball Trophy with his Dancing With the Stars pro partner Kym Johnson, sources tell Us Weekly.

The Shark Tank personality, 51, has been getting cozy with the fancy footer, 38, an insider says. The pair performed together for the first time on the season premiere of DWTS on Monday, March 16, earning an impressive score of 28 out of 40 for their dance to LunchMoney Lewis' "Bills."

Herjavec snuggled up to Johnson at an intimate viewing party for the show on Monday evening at L.A.'s Hyde Sunset Kitchen + Cocktails, where an eyewitness saw the couple holding hands and dancing closely. The partners even snuck in a couple of kisses. After placing fourth in Monday night's episode, the twosome left the studio lot together, speeding off to the party in Herjavec's swanky Rolls-Royce. 

"Kym and Robert were definitely attracted to each other from the get-go," a second source tells Us Weekly. "They are constantly all over each other. She can't stop talking about what a good, nice guy he is. They have insane chemistry and are actually a great match."

The millionaire is in the process of splitting from his wife Diane Plese. He confirmed earlier this month that he and the mother of his three children were parting ways after a 25-year marriage. 

Australian dancer Johnson has never been married. She was previously engaged to cricket player Shane Watson, but the two split after three years together in the mid-2000s. 

"I've never been opposed to dating someone famous," she said in an interview with Australia's Daily Telegraph in 2012. "I'm looking for a good person I connect with... I can't imagine myself without kids... I really want to be a mum. Hopefully I can find the right man."