Brendan Hanrahan shivered in his Speedo as he stood on the corner of Independence Avenue and First Street Southeast. 

It was Valentine’s Day 2010, just days after Snowmageddon slammed Washington, D.C. The streets were barely plowed, and snow blanketed Capitol Hill.

Passers-by wore scarves and mittens — and looks of absolute horror — when they saw Hanrahan’s bare, goose-pimpled skin. 

The 25-year-old patiently waited next to the Cannon House Office Building. 

Within minutes, dozens of people came into view. They were sprinting toward him from the Eastern Market area, and all of them wore nothing but their skivvies. 

It was an “iconic picture,” Hanrahan recalls: tighty whities, hot pink bras and boxers with heart-shaped polka dots, and the elegant Capitol in the background. 

Girls in lingerie, guys in diapers, a few people in Cupid ensembles with bows in hand and wings at their backs. The half-naked crowd stood in stark contrast to the suited men and women who normally walk the Capitol grounds. 

People stared, drivers parked their cars in the middle of the road and Hanrahan was proud. The Cupid’s Undie Run, his brainchild charity event, was off to a great start.

An Unorthodox Idea 

For many, the debut of Hanrahan’s one-mile run in underpants was a chance to do an outlandish once-in-a-lifetime streak. For Hill residents, it was also a good laugh.

But Hanrahan organized the event for a more sobering cause. The Cupid’s Undie Run raises proceeds for the Children’s Tumor Foundation.

Hanrahan was inspired by his best friend’s little brother, Drew Leathers, who was an aspiring football player when he was diagnosed with neurofibromatosis in high school. His life turned topsy-turvy, and he was bedridden for two years. 

Leather’s condition changed Hanrahan’s life, too, motivating him to organize his own charity benefit to fund research for a cure. He settled on a yearly Valentine’s Day-themed charity run on the Hill … in 20-something degree weather … half-naked. 

“People here are young, active and do crazy things, and when you put together underwear, drinking and a good cause, you’ve got a perfect combo,” he said between sips of beer at a bar.

The crazy idea perfectly reflects Hanrahan’s personality. A laid-back yet sharp individual, he’s a fan of beer and thrives on extreme sports. In June, for example, he competed in France’s Ironman triathlon.

He’s also extremely motivated: He is a fifth-year Ph.D. candidate at the University of Maryland and dreams of owning his own engineering company.

With the help of several friends, Hanrahan organized the Cupid’s Undie Run last year using nothing but Facebook, Twitter and word of mouth to advertise. He pitched the idea to the Pour House, which agreed to host the pre-run drinking fest.

Considering the lack of publicity and last February’s snowstorm, Hanrahan figured the event would be a bust. He didn’t even bother securing a city permit.

“I thought I could convince maybe 50 of my friends into doing it, but overall I drastically underestimated how many people would show up,” he said.

Fifty turned out to be 500. People lined up around the block to get into the Pour House and prep for the run. 

They raised $12,000 that day.

The Power of Underpants

If you strip, they will come — at least that’s what Hanrahan learned last year. 

Sarah Morley of Denver fell and tore three ligaments in her ankle during the last Cupid Undie Run, but she enjoyed the race so much that she’s flying to D.C. to do it again.

“How far can we take this?” asked a group of excited women who hoped to wear pasties. “Please,” Hanrahan responded, “no thongs and no pasties.”

The Cupid’s Undie Run has also received attention from the Travel Channel, which added it to a list of “Anti-Valentine’s Day” events. It was also ranked one of five top Valentine’s Day runs on Active.com. 

Individuals and businesses in Chicago, New York and Miami have even asked Hanrahan to collaborate on undie runs in their towns. 

Hanrahan is baffled by the event’s growth, especially since organizers have yet to land a large-scale sponsor. 

“We just rely on the nature of running in underpants in the cold,” he joked.

In the future he hopes to catch the attention of Hanes or Victoria’s Secret, gain even more publicity and raise hundreds of thousands of dollars for the CTF.

This year’s charity run sold out in early January, capped at 500 participants who have thus far quadrupled last year’s fundraising amount. Participants have raised $50,000.

Hanrahan is prepared for an even bigger crowd of spectators this year. He secured several city permits and was granted permission to block off parts of Pennsylvania and Independence avenues Southeast and First Street behind the Capitol. 

And if the Pour House gets too crowded, Hanrahan designated the 18th Amendment as the “overflow bar.”

Eighteen Capitol Police and Metropolitan Police Department officers will be monitoring the run, ensuring participants don’t get too fresh and strip down further. 

As for Hanrahan, he’s just happy to give the CTF and people like Drew Leathers a microphone. 

The Cupid’s Undie Run is scheduled for 2 p.m. Saturday. The party starts at the Pour House at noon. Look for Hanrahan in a Superman belt and red boxer briefs that read “Cupid CEO” on the back.