The good news: The "Party Down" reunion is being televised August 25 on Adult Swim's "Childrens Hospital." The bad: Adam Scott isn't part of it.

Adult Swim allowed me an early peek at the episode -- shockingly titled "Party Down" -- and I can attest that the reunion of the cult 2009-10 sitcom's cast, while brief, is awesome in every way such things can be awesome.

Well, with one notable exception: A certain purveyor of the catchphrase "Are we having fun yet?" is conspicuously absent from the proceedings.

Also read: 'Party Down' Movie and 6 Other Moments From the Cast Reunion [5]

Did the current "Parks and Recreation" co-star have a falling out with Megan Mullally, Ken Marino, Lizzy Caplan, Martin Starr and Ryan Hansen, the five "Party Down" alums who turn up in character in the "Childrens Hospital" episode, which revolves around a catered bar mitzvah that takes place at the clown-infested medical facility?

I asked Scott himself to explain.

"How do I put this diplomatically," he said, during an exclusive interview Monday night at a star-studded NBC bash at the Television Critics Association's press tour. "Rob Corddry and I don't always see eye-to-eye."

Scott -- who played disgruntled actor Henry Pollard on the acclaimed Starz comedy, which ran for two seasons and 20 episodes -- paused before continuing his assault on the bald-pated "Childrens Hospital" creator and star.

"But that’s just because I’m like an inch shorter than he is."

Scott explained in all seriousness that the "Childrens Hospital" shoot date for the reunion conflicted with his schedule on a movie he was filming in New York.

"I wanted to come out for it but I couldn’t," he said. "I got photos from the set and still have them on my phone. It broke my heart not to be there."

Interestingly, Scott will guest-star on a different Adult Swim series in August. He'll play dirty wheelchair-bound agent Van Van Damme on the August 11 episode of Paul Scheer's police procedural parody "NTSF: SD: SUV." Scott joked that he prepared for the role by "watching 'Born on the Fourth of July.'"

Scott also confirmed that he'll be returning for one episode as Kenny Powers' agent Pat Anderson in the upcoming third season of "Eastbound and Down." He said that he'll film his episode in a few weeks.

But what's happening on "Parks and Recreation," which returns for its fourth season on September 22?

"The cliffhanger was Leslie [Amy Poehler] might have to choose between her career and her relationship with my character [Ben] so the season premiere kind of addresses that conundrum," he said. "But I can’t really say more than that."

When pressed to reveal more tidbits, Scott did offer up one juicy spoiler.

"Someone in the cast is a vampire," he teased. "I’m not going to say who. But her name rhymes with Mashida Rones."

If you believe that one, we have a Soup R' Crackers franchise to sell you.