Sometimes you reunite with your ex long after breaking up. That’s what Brad Pitt and Jennifer Aniston have done, but in a total Hollywood way.

This weekend, the actor was spotted outside Jennifer’s birthday party at the Sunset Tower Hotel in Los Angeles, People magazine confirmed. The 55-year-old heartthrob made a casual entrance into the hotel, where his ex-wife held the bash. And he apparently arrived at the hotspot with his long hair slicked back underneath a cap.

A source told People that party guests also included Brad’s other ex Gwyneth Paltrow, as well as Jennifer’s ex John Mayer and John’s ex Katy Perry, who was joined by boyfriend Orlando Bloom.

It ain’t a Hollywood party till you see exes of exes! 

Other folks like George and Amal Clooney, Reese Witherspoon, Robert Downey Jr., Ellen DeGeneres, Barbra Streisand, Keith Richards, Kate Hudson, Laura Dern, Demi Moore and Jennifer Meyer also attended.