Pitt and Aniston divorced in 2005 after five years of marriage, and the source shared that he didn't have her cell phone number and tracked it down through “a tangled web” of contacts to wish her a happy birthday on Feb. 11.
“They started talking once he wished her a happy birthday," the source explained, adding that Pitt “has confided in Jen.”
“Brad told her he’s having a hard time with his split and they exchanged a few texts reminiscing about the past.”
Aniston married Justin Theroux in 2015, and the insider says he's not worried about Pitt's contact with Aniston.
“Justin is OK with them being friends,” the source said, adding that Theroux knows “Jen just wants to be nice.”
See Angelina Jolie's First Appearance Since Split With Brad Pitt
Justin Theroux Wishes Wife, Jennifer Aniston Happy Birthday With Sweet Selfie
Brad Pitt and Angelina Jolie Reach Agreement to Keep Court Documents Private