Although they are much more likely than the girl next door to get divorced (35% have been divorced, versus 23% for the general population), they are also much less likely to get married in the first place.

FORBES: The Liz Taylor Syndrome

As long as Brad and Angie make sure they have their estate in order so their children are provided for should something happen to them, why get married?

FORBES: Why Brad and Angelina Shouldn't Get Married