Kim Kardashian's Brother Rob Addresses Elephant in the Ballroom After 'Dancing With the Stars'

"We support anything my sister deals with," he said backstage, "and that's all we can do."

By most standards, Rob Kardashian enjoyed a red letter night on Dancing With the Stars. He and partner Cheryl Burke tied their highest score of the season, and they brought the audience to its feet a second time during their winning team Paso Doble.

And though it was never mentioned during the broadcast, many in the studio were talking about the day's news of his sister Kim's impending divorce from Kris Humphries.

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"Everybody, obviously, is not in a good mood," he said backstage after the show, "but we support anything my sister deals with, and that's all we can do."

Kim's been a fixture in the Dancing With the Stars audience throughout the season, taking in many episodes with their mother Kris. Neither made it to Monday's show, but Rob did not go unrepresented by the Kardashian clan.

Stepfather Bruce Jenner, sister Kourtney, brother-in-law Scott Disick and nephew Mason were all in attendance -- the latter three decked out in their Halloween costumes.

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"Mason's the best," Rob said. "Now he's trick-or-treating. They came to support me, and then they shook out of here."

Rob and Cheryl have both been candid about the fact that they didn't think he would make it this far into the season. Rob says his stepfather shares the sentiment, but it's only made him prouder.

"He's very surprised and he loves what Cheryl's doing to me," says Rob, "and the fact that it's something that's completely out of my character."

As for his own Halloween plans, Rob joked about the free costumes the theme performances afforded him, but in the end, he had no plans to go out and celebrate.

"I'm going home, showering, probably ordering 20 boxes of pizza and going to bed," he said.