Page Six says so.

…”JUSTIN Timberlake has shown Cameron Diaz the door, so he can sow his wild oats. The hit-making horndog axed his love of three years because, “he’s poised to leave on a world tour and he wants to be free,” says veteran gossip Janet Charlton, whose new Web site, janetcharltonshollywood.com, debuts today. She says Timberlake made his decision after he and his pals went on a stag weekend to Las Vegas and Cameron “went chasing after him. She was just too clingy.” Diaz, said to be “devastated,” has had bad luck before. Her past flames include Matt Dillon and Jared Leto. “

I don’t care much if it is true…but I did like them as a couple. Plus, you gotta consider the source… Page Six ain’t known for their facts.