Jennifer Aniston & Justin Theroux Separately Attended Jimmy Kimmel's Son Billy's Birthday Party

Jennifer Aniston and Justin Theroux may not be together anymore, but they can still join friends in a celebration.

The two stars were both in attendance, separately, at Jimmy Kimmel‘s one-year-old son Billy‘s birthday party on Saturday (April 21).

PHOTOS: Check out the latest pics of Jennifer Aniston

It’s not known if the two mingled at the event.

Justin posted pictures of himself with Billy on Instagram on Sunday (April 23).

“Happy ONE year birthday Billy! 🎂 A boy who in 365 days has done more for American national health care than we could all wish to do in our lifetimes. He doesn’t even know yet how courageous he is. An honor to know him and his incredible and equally courageous parents. ❤️ Thank you @CedarsSinai & @ChildrensLA #registertovote,” he wrote.

If you didn’t know, Jimmy officiated Jennifer and Justin‘s wedding and hosted Justin‘s bachelor party.