Ashton Kutcher, Mila Kunis Make Out in Burbank as Demi Moore Divorce Battle Heats Up

USMagazine, Friday, March 8, 2013, 1:45pm (PST)

Sparks may fly now that Demi Moore has officially filed divorce papers against estranged husband Ashton Kutcher. But for the moment, at least, Kutcher is just fine generating heat with girlfriend Mila Kunis.

PHOTOS: Ashton and Demi in happier times

A source tells Us Weekly that the former That '70s Show costars were "all over each other" while having lunch together in the cafeteria on the Warner Bros. lot on Wednesday, March 6. There was "major kissing," the eyewitness says of the Two and a Half Men actor, 35, and the Oz the Great and Powerful actress, 29, who first stepped out together in March 2012.

PHOTOS: Mila and Ashton's sexy romance

The couple's PDA-packed meal occurred on the same day Page Six reported that Moore, 50, was preparing to file her own divorce papers in response to Kutcher's filing in December. On Thursday, March 7 -- 16 months after she announced the end of their six-year marriage -- the LOL actress officially pulled the trigger and submitted documents to Los Angeles Superior Court.

PHOTOS: Demi through the years

Like Kutcher, Moore cited irreconcilable differences as the reason behind their split. Unlike her soon-to-be ex, however, she is requesting spousal support and seeks to have the actor pay her attorney fees. A source told Us that she had hoped to reach a settlement in private but "was tired of waiting."

"One always hopes that you can negotiate these things and do them under the radar," the insider said. "Nobody wants to be public. But a certain point you need to move forward."

This article originally appeared on Usmagazine.com: Ashton Kutcher, Mila Kunis Make Out in Burbank as Demi Moore Divorce Battle Heats Up