03/10/2005 at 11:55 AM EST
Nicole Richie and Paris Hilton have been friends since childhood – close enough to be each other's accessory – but these days the pair seem to be drifting apart.
These days the pals, in their third season on FOX's reality show The Simple Life, are rarely seen together off duty. Both attended the Vanity Fair Oscar party but kept their distance: Paris hung out with her sister Nicky, while Richie stuck with her fiancé, Adam Goldstein (a.k.a. DJ AM). A few days later they were spotted at the hot Beverly Hills eatery Mr. Chow. Paris was seated first. Nicole came in afterward and went to the other side of the restaurant, out of Paris's view.
A friend of both says the rift is growing in direct proportion to Richie's increasing emotional maturity – even though, at 23, she's a whole seven months younger than Hilton.
"Nicole has grown up a lot," says the source, "and Paris is still being Paris." To wit: Richie is engaged, has quit smoking and drinking and reduced her body piercings from six to one (on the ear).
"I will go to some parties and stuff, but I really just don't have time," she recently told PEOPLE. With an album and two books in the works, "I have so much on my plate."
And, say several sources familiar with the situation at Simple Life, fewer leafy greens in her contract. The sources say Hilton gets the higher pay (she's earning an estimated $5 million for this season's Life) and that has made for one riled Richie.
"They worked through that," says one insider, not clarifying whether their earnings are now on a par. And someone close to Richie says "she's very happy" with what she earns.
At any rate, at least they're working together. When they shot Life in Nashville recently, "there was no static," says a shop owner who saw them. But "they weren't overly giggly either."
And Richie doesn't rule out Simple Life 4, depending on what the producers cook up. "If they let me stay in a resort," she says, "then I would do it."