Some friendships just can’t survive dueling sex tapes.

After all, Paris Hilton was a no-show at former best friend Kim Kardashian’s birthday party in Las Vegas on Friday - and the word is that the two pals are no more due to a clash of egos.

Various sources have confirmed that this friendship between the truly rich and useless has soured ever since Kardashian and her giant boobs began to steal the publicity thunder from the formerly naked Hilton.

“Even when I would talk to editors of magazines and other media outlets about featuring Kim, they would comment on how they are moving past Paris in hopes to bring someone fresh to the spotlight, like Kim,” Kardashian’s ex-rep, Jonathan Jaxson noted on his blog.

Moreover, the former PR man claims that Paris Hilton’s other ex-BFF, Britney Spears, broke off their friendship because she was worried about her image.

“Britney had her people contact Paris and say they couldn’t hang out any more,” he wrote.

From there, Jaxson claims that Spears wooed Kardashian, perhaps to get in touch with her step-brother and well-known ladies man, Brody Jenner.

“Britney was in NYC and kept texting Kim to hang out and go bowling or something,” he blogs, but said Kardashian passed on the invite because she was afraid Hilton would get upset and because she was worried about Spears’ wild ways.

So raise a glass and pour a little of your drink on the floor in honor of this lost friendship, readers. We wonder if nude Kim Kardashian would put her clothes back on and throw Ray J off her if she knew back then what the sex tape would do to her bond with Paris.

Then again, we don’t really care. We just hope the rumored Lauren Conrad sex tape doesn’t affect her friendship with Whitney Port.