‘Funniest thing I’ve ever done’

A mother’s spectacular fail during a school field day left her — and spectators — red in the face, but not due to the exercise.

The moment 36-year-old Katie Hannaford, from Basildon, Essex, England, dropped to her knees and mooned the crowd of young students and their parents was captured in a recent video, South West News Service reported.

Hannaford told SWNS that she’d been strong-armed by her 8-year-old daughter to participate in the relay on June 15.

The homewares business owner furthermore confessed that she’s “not sporty,” and claimed, “I knew I’d come last.”

In the footage, Hannaford is seen starting the race, then quickly falling behind before she ultimately face-plants on the grass, which sees her knee-length dress flip up over her head to reveal her black thong and white buttocks.

“I just tripped over my own feet. I think my body was just moving too fast for my legs! I’m so clumsy,” Hannaford insisted to SWNS.

“I was humiliated at the time, but it is what it is!” she continued. “I flashed my underwear, which is obviously embarrassing but you just have to own it.”

Luckily, she can see the humor in the awkward situation.

“Looking back, it’s hilarious,” she declared. “Definitely the funniest thing I’ve ever done in my life!”