Jon Gosselin and Deanna Hummel Caught on Film!

Uh-oh; Jon Gosselin better get packing a little faster than he planned to.

Us Magazine has a new photo of the Jon & Kate Plus 8 dad getting cozy with his alleged mistress, schoolteacher Deanna Hummel, in Park City, Utah—on his wife Kate Gosselin’s 34th birthday!

The magazine’s photographic evidence shows Jon and Hummel at the Spring Gruv festival at The Canyons Ski Resort in Park City on May 28, the same day that Gosselin turned the big 3-4. Gosselin was on hand to demonstrate his charitable work with handicapped kids, but it seems that he might have been helping himself to a little action on the side while he was at it.

While Gosselin and Hummel wisely chose to keep things on the down-low while the shutterbugs clicked away, witnesses at the Spring Gruv event, a witness recalls them seeming something a little more than platonic.

“There wasn’t any making out or handholding,”‘ says the witness, “but there was that whole girly-smiley-chatty thing. She didn’t seem like somebody he’d just met. It seemed like two people having a great afternoon.”

Later, when Gosselin and Hummel retired to the bar downstairs, “they were curled up in one of the booth seats and very cuddly,” the witness continues. “Nobody was put off or surprised by it at all.”

The onlooker also notes that Gosselin “was so smashed, his eyes were barely open.”

But probably not as smashed as he’s going to get when Kate gets wind of this.

Readers, have your say in the comments section: Do you think Jon and Kate Gosselin are heading for an inevitable break-up?