Khloe Kardashian is expected to file for divorce from Lamar Odom on Dec. 13, according to TMZ sources.

"Lamar's bizarre freestyle rap video, in which he brags about cheating on Khloe, was the last straw in their crumbling relationship. Immediately after TMZ posted the video last month, Khloe stopped wearing her wedding ring," TMZ reports.

The Kardashian sister is reportedly citing irreconcilable differences as the reason for their split.

"Surprisingly, Khloe wasn't upset about the cheating confession, but the video which proved to her that Lamar is continually abusing drugs and alcohol. He was obviously wasted when the video was recorded," a source told Radar. "After she saw the video, Khloe demanded Lamar go to rehab... but he refused. Lamar admitted being under the influence when the video was shot, but insisted to his wife that he was once again sober."

However, Kardashian seems to be ready to go through with the legal separation. The couple has an "ironclad prenup" and no children together, so the divorce expected to go smoothly. Kardashian and Odom have been married since September 2009.

According to multiple reports, the Kardashian has been concerned about Odom's alleged crack cocaine addiction. She has been asking Odom to check himself into a treatment facility, but the NBA player has reportedly refused to get help.

"She flip-flopped several times, but she can't imagine having kids with someone who refuses to seek help for his disease," a source told Us Weekly.