The 39-year-old actor was at the same event as Bruce and Brody Jenner earlier this week, but went out of his way to avoid the reality show's film crew.
"The organizers know how Leo feels about cameras, so they gave him a heads up," a source tells Us Weekly. "He didn't want to be filmed for the show, he wouldn't have wanted to be filmed for anything, but especially not that one."
The star reportedly "waited until they were done filming" before he linked up with friends and "had a great time." The event was a birthday party for Frankie Delgado, and Brody Jenner DJed the celebration for his friend and The Hills costar.