Tennis ace Andy Roddick has slammed reports he's dating Maria Sharapova, insisting they are simply tour buddies. The American sports star, 24, who previously dated pop star Mandy Moore, is furious over rumours linking him to the teenage Russian beauty and has vowed not to let them ruin their friendship. He says, "We're not dating. "I've said it a million times already. "You know, we're friendly. We're in the same places. I think she's a great girl. You know, we'll talk. That's about it."