Rob and Kim Kardashian
FilmMagic; Albert Michael/Startraks
11/01/2011 AT 08:35 AM EDT
The close-knit Kardashian family
certainly sticks together through thick and thin, and Kim Kardashian
's impending divorce from Kris Humphries
is no exception to this rule.
, in good spirits and seemingly unfazed by his sister Kim's marital problems, turned in his strongest performance to date Monday on Dancing with the Stars
Speaking afterwards, he said the family is offering Kim unconditional support during a difficult time
"Obviously she's going through a lot right now, but she has her family and we're very supportive of everything she does and every decision that she makes," he told PEOPLE after the taping, as he stood arm in arm with partner Cheryl Burke
Rob also had family encouragement on Monday – sister Kourtney
was in the ballroom with her 22-month-old son
, Mason, and boyfriend, Scott Disick, cheering him on from the audience, as did stepfather Bruce Jenner.
On their blogs, sisters Kourtney and Khloé also offered words of support to their sister.
, "Our sister is going through a difficult time but we're a close family and are sticking together like always. Kim, we love you.
We appreciate everyone’s kindness and support."
: “I just want to thank all of our amazing fans for your unconditional love and support. My sister is going through a very difficult time and your kindness right now means the world to all of us. Kim, we love you more than anything."