"William went berserk," says a royal insider.
"She made a fool out of me!" he yelled, just days after their FaceTime chat about mental health awareness went viral.
"I thought she truly cared, but clearly I was wrong!"
The controversy erupted over Gaga's "Princess Die" lyrics. In blatant references to Diana's 1997 death in a Paris car wreck, Gaga hints William's mother was suicidal and "took pills" after "downing a peroxide shot."
She later sings, "So bob your head for another dead blonde. She just wants to sleep."
"William and his brother, Harry, are devastated," says the insider. "They feel betrayed."
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