They shared the same delivery weekend, but no way will Christina Aguilera and Nicole Richie share a magazine cover - not if Aguilera has anything to say about it.  Despite negotiations which took several weeks, Aguilera has nixed a deal with OK! Magazine for an issue which was supposed to contain photos of the diva and her new baby, Max. Because the magazine couldn’t guarantee a full-cover photo, Christina walked.

The decision not to give her the full cover, according to one “insider,” stems from the wedding photo spread the magazine previously did on Aguilera. The source says the issue didn’t sell as well as the magazine had hoped, proving she’s not a big seller when it comes to print media. Another source, who is supposed to be familiar with Christina’s magazine contracts, says Aguilera’s contract states no magazine running photos of Max may run photos of Richie and her new baby. “Christina can’t stand Nicole,” said one source.

OK! Magazine says they cannot comment on celebrity contracts.