These headlines must make Angelina Jolie fume with jealousy!

Brad Pitt made headlines by attending Jennifer Aniston's star-studded birthday party this past weekend, but apparently the exes have been growing their friendship behind the scenes for a while now.

After the May 2016 death of the actress' mom Nancy Dow, the War Machine star picked up the phone to offer his condolences, and that's what got the ball rolling for them to reconnect.

"Brad contacted Jen after her mom died, and she was touched that he knew what a difficult time it was,” a source dished to Us Weekly.

As for his decision to grab the spotlight at her b-day soiree?

"He was invited, so why shouldn’t he go? He’s single and has no one to answer to. He and Jen spent many important and happy years together. He obviously decided to join her celebration because he wanted to," another insider told People.

"Her friends were happy to see Brad at the party. Whatever caused their divorce is long in the past. Brad and Jen have a very civil relationship," the source added.

It would be wild if they got back together!