Nicole Richie has threatened to boycott American Idol unless Mariah Carey "makes someone sing from a bathtub full of champagne".

The reality TV star-turned-fashion designer joked about her hopes for the new season of the talent show. Nicole's viewing pleasure will be increased if supposed diva and new American Idol judge Mariah makes outrageous demands on the contestants.

Nicole used her Twitter account to tell her followers what she is expecting from the new addition to the judging panel.

"If Mariah Carey doesn't make someone sing from a bathtub full of champagne on American Idol-I boycott the show," Nicole tweeted. "TRUTH (sic)."

Mariah isn't the only celebrity Nicole's casted her opinion on via the social network site. The American Idol super fan spoke out about the rumoured signing of P. Diddy to her favourite TV show. She joked about the numerous name changes the rapper has enjoyed over his career, saying she might consider a new moniker one day.

"im sick of Diddy having all the fun, I'm gonna make my kids call me Mimmy," Nicole tweeted. "I'll let you know how it goes...(sic)"