Well, you know what they say — one's company, two's a crowd, and three's a pAArty! Ha!
The triple date all went down Saturday night at Chateau Marmont in West Hollywood, where Rob, Kristen and Katy were seen seemingly having a good time on the patio!
"They are obviously very close to Katy. She was very happy having her girls' night out, but when Rob and Kristen arrived she was really pleased to see them. The group seemed to be having lots of fun together. They were laughing a lot and were really enjoying themselves."
Not a bad power couple to be friends with, Katy!
As for the R.Pattz and K.Stew PDA?
An onlooker spills:
"Rob and Kristen weren't overly affectionate in any way; they were not holding hands, but they stayed by one another's side all night. It was obviously a very low-key night for them as they were not dressed up at all."
Seems like Katy and Kristen have been getting pretty close to BFF status…and who would mind super hot Rob tagging along?!?
What do U think of the threesome???
[Image via WENN.]