Maybe she’s hangry! Christina Aguilera looked amazing on stage at a recent concert in Mexico. So great that some whispered the 43-year-old had turned to weight-loss drugs to help her shed 40 pounds or so from her 5-foot-2 frame. Whatever she did, insiders exclusively tell Life & Style that the slimdown has not improved the mom of one’s mood. “She may look great but her attitude absolutely stinks,” a source exclusively tells Life & Style.

“She’s snapping at people and has zero patience. Everybody’s convinced her starvation diet is to blame for her constant bad mood.” The source adds that the “Beautiful” singer’s partner, Matt Rutler, is bearing the brunt of her ire. “He’s proud of her for getting into such great shape,” adds the source. “But he didn’t even think the extreme weight loss was necessary!”