he I Kissed a Girl singer is known to be good friends with the hunky Twilight star.
On Sunday, the pals were spotted together at a wedding event at San Ysidro Ranch in Perry’s hometown of Santa Barbara, California.
Apparently their presence came as a complete shock to fellow guests, as well as the bride and groom.
Life & Style reports a star-struck guest named Zooni Khosla tweeted about the surprise celeb appearance.
“Robert Pattinson is in the same room as me #omg #fangirlmoment,” she posted, adding, “He’s not part of our wedding.”
According to People magazine, Katy, 28, was dressed in a hoodie and oversized sunglasses when she dropped into the event.
An insider insisted it was just a friendly outing for the singer and newly-single actor, who recently split with on/off girlfriend Kristen Stewart.
“Katy and Rob were just sitting next to each other watching the wedding rehearsal in the main courtyard area,” the source told People.
“There was no PDA between them and no body language that showed they were dating. They just sat together and watched.”
Perry is said to be helping Pattinson through his recent break-up.
R-Patz reportedly moved out of the Los Angeles home he shared with Stewart last week. The pair have been on and off since her cheating scandal with married director Rupert Sanders hit headlines last year.
A source previously told Life & Style that is was Katy who encouraged Rob to break it off.
“Katy told Rob she didn’t think their relationship could withstand the cheating scandal,” the insider said. “And he deserved better.”