In a video posted to Instagram, the singer shared that Hart’s trousers had split moments before the couple were due to walk the red carpet.
The pair, who have been married since 2006, attended the ceremony with their two children; daughter Willow, 11, and son Jameson, five.
“I’ve been telling you guys that Mr Hart has a juicy booty. He ripped his pants,” Pink joked in the video, which has received more than 88,000 likes.
A friend who was also present in the room added: “His whole bum just bust through the back of his trousers, screaming.”
Pink then walked over to film her husband in the bathroom and asked him: “What happened?”
“Nothing, literally just the ass blew out of my pants,” Hart replied.
The family opted for coordinated outfits on the red carpet, with Hart and their children opting for all-black looks.
Pink matched her family in a beaded vintage dress by Bob Mackie featuring a lightning bolt cut out on the front. She completed the look with black heeled sandals and large hoop earrings.
The singer took to the stage at the Microsoft Theatre on Sunday to perform “Hopelessly Devoted To You” in honour of Olivia Newton-John, who died of breast cancer in August.
Ahead of the awards, Pink told Entertainment Tonight that Willow had helped her prepare for the performance.
“She was an absolute icon, and also, she was a wonderful human being. I loved her voice,” Pink said of Newton-John.
“My daughter just got done doing Grease in her theatre production, and she actually helped me learn the song.”
Pink previously paid tribute to Newton-John on Instagram shortly after news of her death broke.
Sharing a black and white photograph of herself with the actor, Pink wrote: “I met her maybe three times- and she was an absolute angel.
“One of the loveliest, kindest, light from within human beings I have ever met. Kindness personified. May she Rest In Peace and may her family be held in love and light during this difficult time.”