Paris Hilton lies again.

The real reason Paris Hilton hasn't given her ex-fiancé, Paris Latsis, back his 24-carat engagement ring is because it's not real. Hilton, who's now fooling around with young Stavros Niarchos, "bought it for herself," giggled our spy. "It's a cubic zirconia. The ring Paris [Latsis] gave her was a much smaller one [from Cartier]. She lied to Us Weekly about it and everyone picked it up.". . . . . .Source