Rumor Mill: Did John Mayer Dine with Jessica Simpson on Saturday?

Following Jessica Simpson's Saturday night dinner with friends, including sis Ashlee Simpson and BFF Ken Paves, there have been a number of Internet rumors claiming that Jess' ex, John Mayer was part of the group.

While OK! can definitely confirm that John and Jess did indeed meet up at Katsuya on Saturday, it might be more complicated than it appears.

"John was in the studio, which is near Katsuya, that night," explains one source. "And like he does most nights — like he did again on Sunday night — he went by Katsuya when he took a break from a 12-hour day in the studio."

And though OK! can reveal that John hung out with Jessica and her friends during his Saturday visit it wasn't exactly hearts and fireworks.

"He said hello and he hung out a little bit but he left separately," the insider tells OK!. "He’s really good friends with Jess' brother-in-law Pete Wentz; he sees Ashlee a lot... It’s not out of the ordinary that he sees them and goes over and hangs out for a while."

"They’ve always been friendly," says the source. "They’re still friendly, but that’s it."