The Cry Me a River singer seemingly doesn't have much sympathy for reality TV star Kim - who filed for divorce from second husband Kris Humphries after just 72 days of marriage - and used the derogatory term to describe her after pretending to invite her on stage.
Performing at the iHeartRadio Live concert in New York, he told the audience: "Ladies and gentlemen, I have a very special guest... Please welcome Kim Kardashian to the stage."
Fans then collectively gasped, according to the New York Post newspaper, when he quickly added: "Nah, just fucking with you! That bitch isn't coming on my stage."
Michael - who married Argentinean model Luisana Lopilato in April - then dedicated his version of Nina Simone's Feeling Good to Kris.
He also said of the couple: "She hurt him, she hurt him! I wish she had hurt me!"
Blindsided
Kris's father William Humphries recently claimed his son had been "blindsided" by the divorce filing and had no idea it was coming.
He said: "There was never a discussion about it - it just came out of nowhere and blindsided Kris.
"How could someone do that? Kris was completely surprised. The news was already published before he found out.
"Kris is hurting, but we're here for him. It's not a nice situation."
Kim flew to Atlanta recently where she filmed her part in a new film, The Marriage Counselor.