Finish the contest in her undies

(chapter originally by hanskumoekk at writing.com)

"Okay okay okay!!" Isabel screamed in desperation as she almost cried with fear of being exposed to the rest of the gym. "I'll finish the match with you, please don't do anything!" she begged Heather.

"Good girl! Finally some sense in you!" Kelly said strictly as if Isabel had been disobeying orders. Heather let go of Isabel's underwear and let pushed Isabel towards the climbing wall again.

Isabel nervously grabbed the wall with her hands and waited for the "go!"...