Kuala Lampur, July 28 -- WARSAW, July 29 - Jennifer Lopez suffered a cheeky wardrobe malfunction during her birthday concert in Poland - but took it in stride with a laugh and a joke for the crowd.

According to Billboard, the pop superstar was performing at the PGE Narodowy stadium in Warsaw on Friday night (July 25) as part of her Up All Night tour when the incident happened.

Lopez had just returned to the stage after a wardrobe change when her backup dancers and singers surprised her with a rousing rendition of Happy Birthday. But in the middle of the celebration, her gold skirt unexpectedly slipped off and dropped to the floor.

"Oh!" she exclaimed on stage. "I'm out here in my underwear. That's gonna be everywhere."

The moment drew...