Jon Stewart crashed ‘Jimmy Kimmel Live' to argue against Jimmy Kimmel-themed Bar Mitzvah

Jimmy Kimmel Live's studio audience erupted when Jon Stewart crashed the show to chide 13-year-old Will Rubin for having a Kimmel themed bar mitzvah.

The segment was supposed to be about Will, 13, of Media, Pennsylvania, talking via satellite with Kimmel about the happy occasion, for which Kimmel had sent a video greeting and an ice sculpture of Guillermo.

But Stewart hijacked the bit, scolding Will for his choice of themes:

"You have your choice of idolizing any talk show host and you could have gone with a Jew. Don't be fooled by his learned looking beard and his puffy, sad eyes. He's not rabbinical, he's just unhealthy," Stewart said of Kimmel, who seemed genuinely surprised to be sharing the stage with the former Daily Show host. "Wouldn't you rather idolize a talk show host who is also circumcised?"

Kimmel said he'd contacted lawyers to discuss suing Rubin for using his theme-song, etc for his celebration but decided the optics would be bad since the guy's only 13 years old. So he settled for half of what his grandparents gave him to celebrate. Rubin announced on the show he's instead giving the grandparents' check to Children's Hospital in Los Angeles, where Kimmel's son recently had open-heart surgery. So this late-night host drama had a happy ending.

Watch the segment in the video above.