"She called me fat for years ... now [she knows] how it feels," says the starlet

Credit: Alberto E. Rodriguez/Getty; Albert L. Ortega/Wireimage

Don’t expect Christina Aguilera to get an apology from Kelly Osbourne.

The Fashion Police cohost, 27, infamously called The Voice mentor, 31, fat on TV, and she’s not retracting any time soon.

“She called me fat for years,” Osbourne, who dropped 50 pounds in 2010, tells Glamour magazine. “I said, ‘F––– you, now you’re fat, too! … Now you know how it feels!”

“I’m sorry,” she continues, “but I stand by that.”

And Osbourne would have no problem telling that to Aguilera directly.

“I make a point on the show never to say anything about anybody that I wouldn’t say directly to their face,” she says. “I’m famous and she’s famous. It doesn’t mean I can’t stand up for myself. I took it for 10 years, and finally decided to be like, ‘You know what? I’m done.’ ”

But that doesn’t mean Osbourne is less critical about herself.

“I didn’t say I wasn’t fat,” she explains. “You will always see in yourself what people used to bully you for. … Everyone called me Kelly Smelly with the Big Belly Whose Dad’s on the Telly. It hurt so badly to be judged like that. Even now, I don’t consider myself skinny.”