Miranda Lambert ‘Constantly Worried’ About What Brendan McLoughlin Is Doing ‘When Her Back Is Turned’

She’s a woman scorned. An insider exclusively tells In Touch that Miranda Lambert is losing her cool after being “humiliated” by husband Brendan McLoughlin, who was caught flirting with a group of women at the singer’s own Nashville bar in June. “Miranda gave Brendan a piece of her mind,” says the source, “and a warning he’d better mind his behavior or else.”

The 40-year-old hasn’t managed to keep the marital turmoil behind closed doors. The insider says insecurities over her relationship with the former cop she wed after a three-month whirlwind courtship are to blame for her recent onstage meltdowns. The Grammy winner notably scolded fans at two recent concerts: On June 29, she paused her performance of “Tin Man” and threatened to “come down there” to a disruptive group; and on July 13, she laid into concertgoers for being distracted. Says the insider, “Miranda’s stressed over her marriage and clearly taking it out on her fans. She’s constantly worried about what Brendan’s up to when her back is turned. So any little thing will trigger her temper.”

Despite her current uneasiness — and a cryptic Instagram post about ditching “anything that isn’t serving you anymore” — Miranda is still trying to make it work with Brendan, 32, says the insider. “Miranda hasn’t pulled the plug on her marriage, nor does she want to. But Brendan will be in the doghouse for a while.”