"Everybody is obviously, you know, not in a good mood, but we support anything my sister deals with and that's all we can do, support her," Rob, 24, told reporters after performing Monday night on Dancing With the Stars.
Pulling the plug on her 72-day marriage to NBA star Humphries, 26, on Monday, Kim cited irreconcilable differences in her divorce filing.
"She is truly in love with love," a source tells Us Weekly of the Kourtney and Kim Take New York star, who dated Humphries for nine months before their lavish $10 million wedding in Montecito, Calif., August 20. "She's always the girl doodling her future husband's name on her notebook. And that's what happened here. She fell for him really hard when she didn't really know him. She got very swept up."