American Idol stars clash onstage and off! Nasty feud between Adam & Kris gets even uglier!

The American Idol version of The Odd Couple, Adam Lambert and Kris Allen, are locked in a bitter feud – over everything from their glaringly different lifestyles to their messy shared living space! 

“Although they are friendly on the surface, there’s a major culture clash between Adam and Kris,” an insider close to the hit FOX show told The ENQUIRER.

“Adam is gay and a very flamboyant guy from L.A., while Kris is a conservative married man from a small Arkansas town.”

Kris is a devout Christian who is heavily involved in his church. 

“He’s usually very easy going and tolerant, but it’s as if he and Adam are from different planets,” continued the insider. 

“And since Adam feels he has become the front-runner in the competition, their relationship has become very strained. 

“Kris believes Adam has become arrogant and incredibly full of himself.” 

Adam, 27, has a beef with Kris, too. He thinks the 23-year-old is “cranky” because he desperately misses his wife Katy – his high school sweetheart whom he married in September. 

“Adam and Kris now go for long periods of time without speaking to one another,” revealed the insider. “You can cut the tension with a knife.”