For Lindsay Lohan, a day without drama is like a day without breathing. Or clubbing. Or posing in couture. The rehabbed, id-driven starlet, who will hit the big 2-1 in little more than a month, reportedly had a less than mature squabble with beau-of-the-moment, Calum Best, on Monday night at their Manhattan hotel.

The New York Post claims Lindsay and the British C-lister engaged in a "screamfest" that began in a penthouse suite and climaxed in the lobby.

"Calum's clothes were torn and, after a few minutes, they got back into the elevator and went back to their room," a spy tells the paper.

There's speculation that the cocaine scandal-deflecting actress was feeling a wee bit peevish over reports that Best not only gathered digits from some models while out on the town with her a few days back (per the Post), but during their recent sojourn in the Bahamas, he actually made a move on a mannequin while LiLo was nearby (per the New York Daily News).

Lohan "was screaming about how Calum was cheating on her," an eyewitness tells the Daily News.

The paper then helpfully plants the seed for a future blowup by alleging that Best was supposedly seen by a room service staffer late last week in the company of another young lady who was not Lindsay.

Seems Calum called for the mini-bar in his suite to be replenished in the early morning hours and told the hotel worker to grab a tip from a pile of nearby cash, purportedly saying, "It's Lindsay's money. I don't care."

Alas, the fledgling but already dysfunctional duo quickly seemed to work through their issues, because they hit several hotspots on both Tuesday and Wednesday night, including the Maxim Hot 100 party (lost little girl Lindsay strangely topped their list), where they were "hanging all over each other," according to E!'s Marc Malkin.

Perhaps Lohan will eventually listen to her pals, one of whom the Post overheard kvetching, "All her friends wish Calum would go back to London. He's just using her."

Next: Britney Eyeing Ryan?