Kim Kardashian wasn't the only one surprised by her fiancé, Kris Humphries' proposal--her sisters, Khloe and Kourtney, were floored too! UsMagazine.com reports that only Kim's mom, Kris Jenner, was aware of the engagement plan.

"I knew it was going to happen because he had shared that with me. So I had a dinner right after," Jenner told UsMagazine.com at a press conference on Wednesday for 'Keeping Up With The Kardashians.'

Khloe revealed everyone else was in the dark. "None of [the rest of] us knew," she said. "We were all sitting there like, 'Kim is so late for dinner and we're starving.' And we're like, 'Where the hell is Kim?'"

"Then she walked in, and we're like, 'Oh my God!'" Khloe said. "But we just thought we were going to a family dinner."