Brad Pitt's mom, Jane wrote a letter to express her anti-gay and this cause Angelina Jolie not happy with her actions. One source said, "She is absolutely mortified. She was almost tearing her hair out she was so incensed by Jane's words. She thought they were hateful." "Angie told Brad that he better talk to his mom immediately and straighten her out…or else the wedding is off!" Source
Angelina Jolie threaten to call off wedding after Brad's mom send anti-gay letter
Source: http://angelinajoliesite.blogspot.com/2012/07/angelina-jolie-threaten-to-call-off.html
