Kate Gosselin

There were only nine Gosselins to be seen on Jon and Kate Gosselin's 10th anniversary.

The couple marked their 10th wedding anniversary on Friday, but Jon, almost predictably, was MIA at the Gosselins' Wernersville, Pa., home. Kate was photographed setting up a moon-bounce castle for her eight children in the yard as the Jon & Kate Plus 8 crew filmed mother and children.

Jon was not spotted at all, Us Weekly reports. His whereabouts remain unknown.

Jon's absence may not be that surprising. Jon and Kate, who've admitted to struggling with their marriage, spent Kate's birthday and Memorial Day weekend apart as well.

As the Gosselins continue to work on their relationship, fellow reality-TV parents Rev. Run and his wife, Justine, whose clan is featured on Run's House, have some advice for the couple.

"Keep your eye on what you cherish," Justine tells People.

Adds Run: "If you cherish your wife and kids, that's where your energy goes."

TVGuide.com's calls and e-mails to TLC were not immediately returned.