Brooke White and Syesha Mercado joined Cook with the lowest number of votes on Wednesday's results show. When asked to predict the loser, Cowell said: "Maybe Kristy -- you know, your time's up this time, sweetheart."
Cook cried but took the eviction in stride. She directed her reprisal of "Forever" to Cowell, who grinned awkwardly.
The telecast also featured performances by "Idol" also-ran Elliott Yamin and Carey, who sang "Bye Bye" from her new album "EMC2."