Guests at the star-studded event were surprised to see Brad, 55, at the party and were “making a big deal of it,” the source continued.
“But it didn’t seem like that big of a deal to Jen. The invite went out to a ton of people and he accepted. She was happy he was there, but that was it. She was busy making the rounds and excited to see so many people near and dear to her.”
Brad was spotted casually making his way to the hotel, where his ex-wife, who officially celebrates her 50th Birthday on Feb 11, hosted her huge bash. The actor arrived at the hotspot with his long hair slicked back underneath a cap, photos show.
Other A-List guests included Pitt’s ex Gwyneth Paltrow, plus Aniston’s ex John Mayer and his ex Katy Perry, who was joined by current boyfriend Orlando Bloom. (still following?)
George and Amal Clooney, Reese Witherspoon, Ellen DeGeneres, Kate Hudson and Demi Moore were also in attendance.
“Brad seemed to have fun and everyone loved seeing him. He was catching up with old friends and enjoyed himself,” the insider told Us
“He saw a lot of people he hadn’t seen in years. Any negative feelings seem to have been put aside by Jen’s friends. It’s been a long time and everyone has moved on. Brad didn’t stay all that long and ducked out before most people.”
After news of Aniston and ex-husband Justin Theroux‘s split in February 2018, a source with knowledge of Pitt and Aniston’s relationship revealed to PEOPLE that Pitt and Aniston — who were married from 2000 to 2005 — had “been over each other for longer than they were ever together.”