If you thought the first Cheyenne Marathon was a fun event, wait until you see the runners in their undies. Cupid's Undie Run is coming to the Capital City for the first time on Saturday, February 16th.

Billed as the "largest pantsless party" in the country, the "brief" one-mile run is a fundraiser for neurofibromatosis, a genetic disorder that affects 1 in every 3,000 children born, and the Children's Tumor Foundation. Since the inaugural Undie Run in Washington D.C. in 2010, the charity has expanded to 40 cities around the world.

"We encourage undies, but we get that it’s not for everyone," said Cheyenne Race Director Melanie Manchester. "Whether you start a team with your friends, join a team, or run solo, just come out, have a blast, and raise some money for NF research!"

To promote the event, organizers are hosting a "Kick Off Cocktail Hour" this Saturday night at 7:30 p.m. at the Little Lotus Yoga Studio in downtown Cheyenne.