All may not be well in Brangelinaland — Angelina reportedly caught Brad dallying with the help late last week. According to Star Magazine

Brad was on the bed, rubbing the back of a pretty young nanny! Angie got so mad she slapped Brad and fired the girl on the spot!

“She completely flipped out,” says the insider. “She got right in Brad’s face, screaming at the top of her lungs, and told the nanny to get out of her house and never come back!”

The explosive argument woke up the sleeping twins, who began to cry. As Brad tried to console both the twins and the nanny, Angie just snapped — and slapped! — hitting him right across the face.

“He was stunned,” reveals the insider.

What makes this all the more shameful is that Angie reportedly used Brad’s own ballsack to slap him in the face. “Keeping his nuts on my person with his spine and what’s left of his free will really comes in handy during an argument,” she’s quoted as saying. I’d have to agree with her there. In my own personal experience, nothing stings quite like a scrotum to the face. But I’m afraid that’s a story for another day!

Angie filming “Salt” in D.C.: