Sabotage her bra

Isabel finished loading the weights onto the bar and laid down on the bench. Once she was situated, Kelly helped her get the bar off the rack, and Isabel began doing her reps. After a few, Kelly chose to take her scheme to the next step.

"Isabel, there's a loose thread coming from your bra..." Kelly said.

"Just leave it alone. I've had...bad experiences when I've pulled loose threads before." Isabel explained.

"Don't worry, I'll just cut it off. I have a small pair of scissors." Kelly said.

"Okay...make it quick!" Isabel said between breaths.

Kelly crouched down so she couldn't see her. She took out her scissors and instead of cutting a loose thread, she cut one of her bra's shoulder straps. She didn't cut completely through it, instead leaving it hanging by a few threads.

"Oh, there's one in your other strap as well. It's a short one, but I can get it." Kelly said, repeating the process on the other side.

Now, Kelly just had to wait...