From PEOPLE Magazine Click to enlarge
It was the smooch seen around the world: Performing the quickstep on Dancing with the Stars Nov. 12, Helio Castroneves, 32, dipped his partner Julianne Hough, 19, and gave her a short but emphatic kiss on the lips. The live audience erupted in applause—but one at-home viewer was less than pleased. "That kiss was the kiss of death," says a friend of Aliette Vazquez, a Miami fashion consultant engaged to Castroneves since 2006. "It ended what had already become a bitter relationship."

On Nov. 28, the day after Castroneves and Hough won the Dancing title, Vazquez, 28, announced her engagement was off. Immediately there was speculation that the Brazilian racecar driver's chemistry with Hough went beyond the dance floor. The duo themselves deny any romance. "We're just good friends," Castroneves tells PEOPLE. Hough, who called off her own engagement to a dental student in May and has since stepped out a few times with Entourage's Kevin Connolly, seconds that: "Gosh, no! I love Helio like he is my brother." And Dancing's Karina Smirnoff (who dates her ex-partner Mario Lopez) adds, "We've never seen anything backstage. I don't think they're [dating]." Still, Vazquez "thought there was something going on" starting with the first episode, says a Castroneves pal. "She didn't feel good about the future with him."

Sources say things had been rocky since Castroneves headed to L.A. in August to train with Hough. Castroneves told TV Guide last month the show "has been a big test" for the relationship. "If something goes wrong ... it's better to find out now."

Now that it has, the Dancing champ is moving on. Performing in the Walt Disney World Christmas Day Parade in Orlando Nov. 29, he and Hough "were all business," says a source. "Nothing out of the ordinary. They seem like friends."

  • Contributors:
  • Monica Rizzo/Los Angeles,
  • Mary Margaret/Los Angeles,
  • Linda Marx/Miami,
  • Steve Helling/Orlando.