"You're in for a really weird night," Kimmel said Tuesday as McHale joined Jimmy Kimmel Live. "You're going to be sitting next to the first lady."
"And she's so hot," exclaimed McHale, who had joked in a tweet earlier this month that his appearance would "show Mrs. Obama who looks good with bangs."
Kimmel -- who is expecting a baby with wife, Molly McNearney, told McHale the gig was "even more exciting than having a child" and told McHale that he'd never been more nervous in his life.
"Have you had your background checked?" Kimmell asked. "Not yet, I'm trying to fix some stuff," McHale replied.
McHale said he's bringing his parents -- and it'll be at least the second time for his dad, who was entranced at the dinner in 2008 by a Pamela Anderson sighting.