Showing what an ass she can be, tempestuous diva CHRISTINA AGUILERA exploded in fury when her fat butt suddenly split her pants during a song-and-dance spot on “The Voice” – and she screamed curses at crew members she’d spotted laughing!

“Christina felt the back of her pants burst open as an assistant costumer rushed onto the set,” said a show source.

“She was embarrassed, but made light of it – until she spotted crew members laughing on the sidelines. Enraged, she shrieked curses at them, snarling that if it wasn’t for her, they wouldn’t have jobs!”

Here’s the sad kicker: “The group of several crew guys and one female were horrified by hothead Christina’s reprimand because they’d been laughing at a story one of them was telling, and not at her. But they didn’t dare fight back, knowing she’d have them fired on the spot!”

NOTE TO CHRISTINA: Fat head’s far worse than a fat ass, La Gorda