Jessica Simpson peed her pants live on the ‘Today’ show

She was singing in the key of P.

Jessica Simpson has joined the pantheon of greats who’ve peed their pants on stage, we hear, after she accidentally let loose live on the “Today” show on Wednesday.

The pop singer performed a medley as part of the NBC breakfast show’s summer concert series, and she’s such a pro that viewers wouldn’t have known anything was amiss.

But Page Six hears that after the “Newlyweds” star returned backstage after her performance, she… spilled… to people in the greenroom.

Those high notes can be hazardous, it seems.

It’s pretty common, in fact. Greats including Pattie Labelle, Fergie, Joe Jonas, Ed Sheeran and Hugh Jackman have all had onstage bathroom mishaps.

Jackman, for example, once said on Rachael Ray’s show that he’d been appearing in “Beauty and the Beast” early in his career, and had been drinking a ton of water to treat headaches.

“I go down to the stage, getting ready for my first number…and I’m like I really need to go again,” he said, “[The routine is] the most cardiovascular song I’ve ever done: literally I’m picking up Belle and as I pick her up, I stopped singing and right in that moment I realized the muscles you need to release in order to sing are the ones you do not want to release if you need to go.”

Anything to make a big splash in showbusiness!