Catfight!!!! Jessica Simpson is jealous of Cameron Diaz.

Jello fight? Cage fight?
Jessica Simpson’s new color is green.
A source close to the singer tells Us Simpson is “really jealous” that ex John Mayer is seeing Cameron Diaz. “She had her mouth open a mile wide when she found out,” says the source. “She just freaked.”
Simpson, 27, parted ways with Mayer, 29, in May after dating him on and off for seven months, and “she thinks about him all the time,” says the source. “She is so not over him.”
Meanwhile, Simpson seems to be a distant memory for Mayer, who has continued his summer romance with Diaz, 35, in NYC. Though they spent August 22 and 23 apart (he hit the gym and recorded at a studio; she shopped and then lunched at Mary’s Fish Camp), they finally squeezed in quality time in the wee hours of August 24 at hot spot Socialista. The pair — who left at 4 a.m. through different exits — “were very cozy,” says a witness.
Echoes a source close to the new couple, “They’re happy.”
(Hello new Geno's World readers! If you're visiting us for the first time, hit the home button to check us out. Bookmark us & come back again! Thanks.)