Chris Hemsworth Decides to Blow Off 'Kimmel,' Party With Guillermo Instead (VIDEO)

When 'Jimmy Kimmel Live' (Weeknights, 12AM ET on ABC) started, there was something different on the set. Being the astute detective that he is, Jimmy Kimmel deduced right away that Guillermo had been replaced by a cardboard cutout. So he went in search of him.

Apparently, Guillermo had decided to celebrate Cinco de Mayo rather than do the show. "I cannot come tonight," he told Jimmy. "I'm sick."

When Jimmy told him there were guests and a show to do and he needed security, Guillermo insisted he had a guest, too. Then, Chris Hemsworth joined him in the celebration.

"That's not your guest," Kimmel said. "That's my guest."

"He cannot come, too. He's sick," Guillermo insisted as Hemsworth played along.

With 'Thor' set to open in the U.S. Friday, May 6, 2011 -- it's already grossed $125 million worldwide -- Hemsworth certainly has reason to celebrate. We agree with Guillermo. Stop being such a party-pooper, Mr. Kimmel!

Watch Chris Hemsworth's full interview here: