Brad Pitt Was at Jennifer Aniston's Birthday Party, Along With the Rest of Hollywood 

Every A-list celebrity in Hollywood, along with a few B+ list hangers-on, was at Jennifer Aniston’s 50th birthday party on Feb. 9. So is it really that weird her ex-husband Brad Pitt was there?

People is reporting that Pitt was seen outside the Sunset Tower Hotel, where the party was held, with his “long hair slicked back under a cap.” Which seems a little casual for a big birthday bash, but I wasn’t invited and don’t know the dress code.

Pitt and Aniston weren’t the only exes in attendance:

A source tells PEOPLE party guests included Pitt’s ex Gwyneth Paltrow, plus Aniston’s ex John Mayer and his ex Katy Perry, who was joined by boyfriend Orlando Bloom.

Courtney Cox and David Arquette rounded out the list of celebrities who shared custody of a friendship with Jen in their split. As for the rest of the guest list, just name someone who commands at least $10 million a picture and that person was there. The exceptions are Angelina Jolie, for obvious reasons, and Charlize Theron, who Pitt is maybe dating, so that tabloid headline writes itself.

That’s a lot of exes in one place. But many of these relationships are decades old. Pitt and Aniston got married nearly 20 years ago. And kids who were born during the Pitt-Paltrow years can now legally rent cars. At some point, running into an ex becomes not all that different from running into a once omnipresent friend that time has turned into what the early 21st century poet Gotye so poignantly terms “Somebody that I used to know.”

It is, however, a testament to how much people like Jen that they would suffer through a night of standing around with exes and currents making polite chitchat about detoxes, botoxes, yacht maintenance, and whatever else celebrities talk about in order to wish her many happy returns.