11/01/2011 at 04:00 PM EDT
To appear or not to appear? That is the question.
The same day she filed for divorce
, Kim Kardashian
jetted off to Australia to launch her Kardashian Kollection purse line at a party in Sydney. Meanwhile, her estranged husband
Kris Humphries is canceling a planned appearance in Las Vegas this weekend.
Humphries, who appeared in sexy shirtless ads to promote the event, was scheduled to host a party Saturday at the Chateau Nightclub inside Sin City's Paris Hotel. But since learning that his wife of 72 days filed for divorce, the "devastated"
basketball player will be a no-show, his rep confirms to PEOPLE.
Humphries, who is at home with family and friends in Minnesota, is "very sad," says a source. "He's just processing it all."
Kardashian, who took off from L.A. Monday night
, is "heartbroken," says a source close to the star. "But she's holding up okay. Neither of them wanted it to end this way."