Jessica Simpson, Nicole Richie Fighting like Crazy on ‘Fashion Star’

Two of the most successful celebrity fashion designers, Jessica Simpson and Nicole Richie, are now working on a new reality series called “Fashion Star.” While the show is not even on air yet, the two are constantly fighting, threatening to pull the plug on the production.

They both seem like very nice girls, but the reality of it is that they’re not – especially if they’re in the same room, The National Enquirer says in its latest print issue (story via here).

Whereas producers assumed a certain amount of competitiveness would do the show wonders because it would attract viewers, it seems that it’s actually ruining it, with Jessica in particular being very mean to Nicole.

She’s also putting on her best diva act, driving people around her insane, sources familiar with the production tell the tab.

“Producers thought pairing them on screen would mean lots of fireworks to attract viewers. But their personalities don’t mesh at all. Behind the scenes, the set is a war zone,” an insider dishes.

Nicole is nice most of the time, with Jessica being the one that chooses to not put an end to the constant fighting, the source explains.

“Nicole is always ready to go, but Jess lingers in her dressing room, keeping everyone waiting and asking to do multiple run-throughs,” the spy goes on to say.

There is also the issue of Jessica’s weight: she’s gained a few more pounds just recently and she’s incredibly sensitive about it, which means it makes her the ideal target for Nicole’s jokes.

“Nicole has made a few digs about Jessica ‘throwing her weight around,’ while Jessica has joked that someone would have to be on a starvation diet to wear Nicole’s designs,” the insider says.

“Now they’re barely talking, which doesn’t bode well for the show’s success – and it isn’t even on the air yet!” the same source adds.

Though there were ever any reports that Jessica is being a diva, it would certainly make sense if she took offense when others joked about her weight, especially since she’s constantly under the microscope: her latest public appearance has already generated pregnancy rumors.