Contrary to yesterday's gossip, player John Mayer may not be dating Mandy Moore after all! It seems we only got half the story. After lunching with Mandy on Tuesday, he had another date lined up for the day -- with Cameron Diaz! "They went out to several places," a source tells Us Weekly. "It was the two of them, getting to know each other, out on the town." Specifically, they went a cozy, late-night dinner where a spy tells Page Six, "They were very playful and cozy" and "lingered over dessert." Oooh, sounds romantic!

So how long has this been going on? "This was technically not their first time hanging out...they've hung out together with friends before. But this was the first time together like this" an insider tells Us. "It's new and developing...but they really like each other and it went well."

As for Mandy, she's likely still dating lesser-known singer/songwriter, Greg Laswell as she told Us Weekly, "Oh my goodness. John and I have been friends for years, no romance."