A shared craving for fame and a complete lack of inhibition apparently wasn't enough to keep several MTV-chronicled reality show C-listers (well, almost) from calling "cut!" on their relationships.

First up are Travis Barker and Shanna Moakler from "Meet the Barkers," who, like Nick and Jessica and Carmen and Dave before them, have reportedly decided to pull the plug on their camera-ready marriage, going their separate ways after less than two years of PDA-crammed coupledom.

Barker, 30, the onetime drummer for Blink-182, filed for divorce on Tuesday, a move Us Weekly says came as a shock to Moakler, 31, a former Miss USA and Playboy Playmate.

"Shanna was caught completely by surprise," an insider tells the magazine. "She was trying to get him to couple's therapy, but he wouldn't go. He pretended he was working things out but screwed her over, leaving her with a baby daughter."

The Barkers have two kids, son Landon, 2, and daughter Alabama, 7 months (Moakler also has a 7-year-old daughter, Atiana, with former fiancé Oscar de la Hoya).

Talk of trouble has been brewing for a while, with the New York Post reporting in May that Barker dumped a drink on Moakler at Las Vegas hot spot Pure (they supposedly had been squabbling over whether Shanna should be a stay-at-home mom). And a couple of weeks back, Moakler reportedly tossed a drink on a woman who was taking a picture with her husband at a Los Angeles nightclub.

The couple, who tied the knot on Halloween Eve in 2004 in an elaborate ceremony inspired by their favorite flick, "The Nightmare Before Christmas," recently put the 12,000-square-foot, 8-bedroom, 10-and-a-half-bath Bel-Air estate where they filmed the show on the market for $8.5 million and purchased a same-sized pad in Calabasas.

Meanwhile, reconciliation wasn't in the cards for erstwhile "Laguna Beach" blondes Kristin Cavallari, 19, and Lauren "LC" Conrad, 20, who are kaput for the second time with respective beaus Brody Jenner, 22, and Jason Wahler, 19.

"Yes, Brody and I broke up," Kristin informs People. "It's just hard right now because I am working all the time. We're still good friends though."

The capricious couple originally went belly-up in March, shortly after Cavallari told Teen People, "Brody is my first mature relationship. I know I'm in love with him."

The starlet was briefly linked to Nick Lachey (long enough to land two Us Weekly covers) before reuniting with Jenner, the star of Fox's quickly canceled "Princes of Malibu," in May.

"They fought a lot," a Cavallari confidante tells Us, with Jenner adding, "It was mutual."

Not so mutual was LC's bust-up with on-again, off-again "Beach" and "The Hills" boyfriend Jason, with her rep telling People, "It's true. Lauren broke up with him last week."

The problem, according to one of her pals, is that their interests no longer meshed.

"He had been going out to clubs, flirting with girls, staying out late," the friend asserts to Us. "She wanted to focus on school and her career and was ready to move on. She feels really good about her decision."

So good, says Us, that Conrad, who is pursuing her fashion design dreams (bad move, though, choosing Jason over that internship in Paris), took some time out of her weekend jaunt to Vegas to have her "Jason" tattoo inked over.