Not very well

10 strikes in, the tears were pouring down her face. 20, she was starting to go numb. 40, she couldn't feel her butt anymore, and her pussy was soaked. By the time Glynda finished her punishment, Ruby was hunched over, a soaking wet mess. Her tears had soaked the gag, and snot was running from her nose. There was a shiny streak going down both of her thighs, which shone brightly thanks to glaring spotlights they were reflecting. Glynda took note of this, and with a final sneer, drove her fingers into Ruby's snatch with merciless force, and began fingering her. It only took a few seconds before, with a final long cry into the soaked gag, Ruby came violently, gushing fluids out onto the dance floor. She sank to her knees, burying her face into her stretched arms as much as she could. Distantly, she felt her binds come loose, and the gag fell away. A hand snatched her arm, and she was dragged up into a sort of standing position, where another hand grabbed her chin and forced her to look out at the crowd. Through her haze, she saw several students blatantly masturbating, quite a few with their scrolls out to record her, and a lot of horny faces.

"Happy birthday, Miss Rose," Glynda said into her ear before jamming her riding crop handle first into Ruby's snatch and dropping her into the puddle of her own fluids. Ruby curled up into a ball, and promptly passed out.