Brad Pitt, Jennifer Aniston reportedly spoil favourite niece Sydney after her graduation

It's been fifteen years since Brad Pitt and Jennifer Aniston ended their marriage, however, the actress has reportedly stayed in touch with a member of her ex-husband's family with whom she had formed a close bond.

Sydney Pitt, daughter of Brad Pitt's brother Doug, was born around the same time he started dating Jennifer Aniston. The "Friends" alum formed a special bond with the newborn and has been close with her ever since.

"Sydney was born right around when Brad and Jen began dating. She was a tiny baby when Brad brought Jen home to Missouri to meet his parents and his brother, Doug – Sydney's dad," an insider told Australian magazine New Idea.

The source added that the bond between Aniston and Sydney bothered Angelina Jolie as well, during her marriage to the "Ad Astra" actor. "Because of that, Jen shares a special bond with her, too. Sydney has always called her Aunt Jen – something that bothered Angelina no end when Brad was married to her," stated the insider.

"Brad and Jen like to think they'd have had a girl just like Sydney, and that they might have even grown up together," the source added.

Sydney Pitt is now an adult and has graduated Drury University in Springfield with a degree in architecture. Her Oscar-winner uncle, who loves her "like his own," has reportedly invited her to celebrate the occasion at his mansion in Santa Barbara, which he bought when married to Aniston. Sydney has visited her uncle's beach mansion in the past as well, spending holidays with her father and siblings Reagan and Landon.

The outlet also stated that Pitt and Aniston are spoiling Sydney as a reward for her academic accomplishments. "I've heard he's even thrown in the use of his beloved Tesla. He trusts Sydney implicitly, as if she was his own daughter. He knew she had a good head on her shoulders when she started showing interest in studying to be an architect," the source continued.

Architecture is a subject that holds special importance for Pitt, who infamously put his movie career on hold to study it with renowned architect Frank Gehry as his tutor.