Jessica Simpson has been thrown into the Tiger-mistress mix by Star magazine, and she's not happy about it.

The tabloid claims to have a source that spotted Tiger Woods and Simpson canoodling at the AT&T National Pro-Am golf tournament over the summer, just days before she broke up with Tony Romo. "Tiger liked what he saw and let her know it," the source says.

But the singer isn't laughing, calling the story "A LIE!" on her Twitter feed.