Yes, that happened. Selena Gomez walked the red carpet at Katy Perry’s movie premiere yesterday and she and Justin Bieber watched Katy’s Hollywood Blvd. performance. After the premiere, Katy threw a party at the Chateau Marmont and Robert Pattinson, along with Bieber and Selena, attended the bash.

After Katy’s shindig, Robert was the last one to make it outside where Justin, Katy and Selena had already jumped into the limousine bus. Whoever was in charge forgot that Patsy was also there and he was momentarily locked out of the vehicle! As you can see in the picture above, Rob thought it was hilarious. Can you imagine if the limo had actually taken off? The Twilight star would have been mobbed!

See, unlike what’s shown in Part of Me, Katy has friends that aren’t on her payroll. Seeing these A-listers party together reminds me of when Britney Spears, Lindsay Lohan and Paris Hilton used to roll together. We like it!