By Breaking Celebrity News Staff

Angelina Jolie was "mortified" after Brad Pitt's mother Jane penned a letter to a Missouri newspaper last week condemning same-sex marriage and President Barack Obama's re-election, Star magazine is reporting.

"Jane has never wanted to talk politics with Angelina," a source told Star. "She knew it would cause greater issues for them, and she wanted to try to have a relationship with the mother of her grandkids. She never thought her letter would be such a big deal."

Jane, in a controversial response letter to the Springfield News-Leader's July 3 edition, wrote, "Any Christian should spend much time in prayer before refusing to vote for a family man with high morals, business experience, who is against abortion, and shares Christian conviction concerning homosexuality just because he is a Mormon."

In the wake of the comments, sources tell Star that Angie -- a staunch advocate of same-sex marriage -- "has told Brad he must educate his mother, but Brad is too much of a mama's boy."