Lindsay Lohan's Tearful Night Out With Sam

After attending a holiday party, LiLo ends up in tears after a fight with Samantha Ronson

Although Lindsay Lohan blogged that she and Sam Ronson are still together, things got rocky for the couple last night. Both girls were in festive spirits Thursday night at a holiday party before things took an ugly turn.

First, the duo hit the MySpace holiday party at Tenjune, where Sam deejayed and L.L. donned a Santa hat and hung with her mom, Dina. "They were in such good spirits," an eyewitness says. "Lindsay kept hopping in and out of the deejay booth, giving Sam plenty of attention."

But apparently LiLo didn't feel like Sam reciprocated when they headed to the NASCAR Sprint party at Marquee.

"Sam was roaming the party and chatting with people, and Lindsay just seemed to melt down literally," an onlooker tells E!.

So what was she so mad about?

L.L. was apparently jealous that her best girl was talking to other people.

Sam reportedly wanted to stay out and Linds didn't. After they started arguing, Lindsay stormed out of the soiree in tears, and Sam eventually ran after her.

They weren't the only girl-girl pair at the party. Aubrey O'Day was also there pretending to be a lesbian, according to an onlooker. "She spoke about Prop 8 and how she and her girlfriend were upset that it passed," a source says.

She also said that her puppy, Ginger, who she was holding, was "also a lesbian."