A source close to Paris tells PEOPLE that Richie is jealous of the media attention her blonder costar receives and resents being left out of things like Hilton's Feb. 5 hosting gig on Saturday Night Live. In fact, says the source, Richie tried to get even for that perceived slight by throwing a party to celebrate the SNL stint and then screening Paris's infamous 2003 sex video instead.
"Paris was very hurt," says the source. "She loves Nicole but believes she is owed an apology." (Reps for Richie deny the incident.)
Meanwhile Richie's friends tell PEOPLE that tensions arose because Nicole has grown out of her wild ways, quitting drinking and spending more time with her fiancé , Adam Goldstein. "She just wants to be with Adam and get married," says one.
Arlene Richie / jpistudios
So is it goodbye Nicole, hello Kimberly? FOX says no decision has been made. In the end the only thing that seems indisputable is that with The Simple Life no longer so simple, both women are moving on. Richie is reportedly shopping a Newlyweds-style series to MTV, while Hilton is promoting her role in the movie House of Wax and waiting to hear if FOX will hire Stewart. And, according to the source close to Hilton, with their onscreen duo a bust, a reconciliation seems unlikely any time soon.
"Nicole sees (the show) as a business that's separate from the personal," says the source, "but Paris doesn't separate the two."