Angelina is one of those women who sees an attached man as a challenge but it was incumbent on Brad to realize his attraction was easy bait for a divorce. Seems like he wanted a reason to leave, that he just got bored. Point is, he wanted out. Some men thrive on unpredictable, complex women. Angelina thrives on baiting and he wantonly followed. Now perhaps Jolie will tire of him. Anyway it won't be easy because they'll continue their patterns with other people of the opposite sex when they run into a "boring" period. He'll find another "intriguing, complex" woman who will flirt and gain his confidence; he'll complain about his life and end up following the other woman around. Angelina will find another reason to fly around the world and avoid problems and being in a settled relationship.
As a side, I really dislike it when men deliberately seek out female friends to complain to about their wives or girlfriends, like the "woe is me, she doesn't do x, y, or z; she's not like you, you're so different." It's an easy way to get another woman's affection, compassion and confidence without sounding like he's trying overtly to flirt or hit on her. Brad's blabbing about Jen and babies etc. with Angelina invited her flirting and baiting and he didn't want to admit it in the end. That's what made me think badly of Brad. It's human nature to be attracted, it's also this thing called intelligence that we remind ourselves of our actions that could lead to marital or relationship strain. I hope Jen finds a solid, self-possessed guy to settle down with in the end.