Karina Smirnoff tells sources "there is nothing" to rumors that she is hooking up with her Dancing With the Stars partner, R&B singer Mario.

"We have a completely professional relationship," she tells Us. "I have a lot of respect for Mario. He is a great person."

The New York Post reports that Mario and Smirnoff (who is dating Mario Lopez) were "making out by the valet with their hands all over each other" at the Four Seasons Hotel in Los Angeles.

Mario's rep also denies the claim, telling Us, "this did not happen."

But a source close to the singer insists "there is definitely chemistry and a flirtation between the two."