Justin Theroux and Jennifer Aniston
Pictured: Justin Theroux and Jennifer Aniston, who recently called it quits, posing during a photocall at the launch of a Louis Vuitton leather goods collection at the Louvre in Paris on April 11, 2017. Getty Images/Gabriel Bouys

Exes Jennifer Anniston and Justin Theroux reportedly almost had an awkward reunion meeting at Jimmy Kimmel’s son Billy’s birthday party.

On Monday, an eyewitness exclusively shared to Us Weekly that Aniston and Theroux missed each other at the Los Angeles party that Kimmel and Molly McNearney threw for their son’s first birthday last Saturday, April 21.

The awkward encounter could have happened had Aniston arrived a little earlier. The eyewitness said Brad Pitt ex-wife arrived at Kimmel’s Hollywood Hills home at around 12:15 p.m. EDT, around which time Theroux was seen leaving.

“Justin spent about 40 minutes at the party. [He] was in and out and acted totally normal,” the eyewitness said. It appears the ex-couple may have been warned of each other’s attendance at the party because Aniston was noticeably “a bit nervous” when she got there.

Aniston went to the party with a girl pal, but the latter was not identified. “She arrived with a girlfriend and was wearing the hand brace on her left hand. [She] left around 2 p.m. [EDT],” the eyewitness shared. “They didn’t see each other.”

Both Aniston and Theroux are good friends with Kimmel and his wife. Aniston recently vacationed in Tahiti with the couple. It should also be noted that Kimmel’s family were present on the exes’ honeymoon trip, according to People.

Theroux is believed to have intentionally avoided the awkward reunion with his ex because of his short appearance at the party. Meanwhile, the “Friends” alum took the time to mingle with guests and send her best wishes to the birthday boy.

Aniston and Theroux tied the knot in August 2015. They announced their split in February, putting an end to their seven-year romance and two-year marriage. “In an effort to reduce any further speculation, we have decided to announce our separation. This decision was mutual and lovingly made at the end of last year,” the pair said in a joint statement at the time.

A source previously divulged that since calling it quits, Aniston and Theroux have barely spoken to each other. Aniston is currently being linked by tabloids to Pitt, but it was found out that they haven’t even seen each other in “ages.” On the other hand, Theroux was recently spotted hanging out with much younger model Erika Cardenas.