In the time since Brad Pitt announced his divorce from Angelina Jolie, he’s found an unlikley source of comfort — his ex-wife, Jennifer Aniston. Though they have a complicated history, Jen has managed to forgive her ex-husband for everything he put her through and the two have found a nice rhythm and are now closer than ever. In fact, they recently took a huge step in their relationship when she met four of his six children at his Los Feliz home.

A source tells In Touch exclusively that it all started when she arrived at his home to drop off a gift — a book about interior design, which is a shared passion of theirs — and she was surprised to see that his four youngest children, 13-year-old Zahara, 11-year-old Shiloh, and nine-year-old twins Vivienne and Knox — were at his home. “It was a momentous day,” an insider tells In Touch. “The kids knew who Jen was and were familiar with her from TV and magazine photos, but they treated her like a normal friend of their father’s.”

Of course, it didn’t take long for the little ones to go and tell their mother — who was understandably not happy. “Of course the kids went right home and told Angelina about meeting ‘that lady Jennifer,’ and, as expected, she went ballistic,” the insider says. “She immediately left word with Brad that she was furious. She told a confidant, ‘Brad’s gone too far.’”

According to the source, it’s unlikely that Brad would want to fight with his ex-wife at this point in time. The two are close to finalizing their divorce and settling their custody dispute. However, when his ex asked to drop off the gift, his kids were already there. The insider adds, “Taking the situation in stride, Brad casually introduced [his kids] to her as they played.” (A rep for Jen denied the story.)