Shelby, 18, a preppy class president

Shelby had it all. She was 18, president of her senior class, drove a little convertible her parents bought her, and very beautiful. She stood 5'10" with bright red hair, straight to her mid-back, with perfect skin, her childhood freckles having completely disappeared since she got on the urine diet, and her skin cleared up to the point where she could appear on a fashion magazine cover without any airbrushing. She'd also lost weight and was now just 115 pounds without starving herself or sacrificing her C-cup breasts.

Getting 2 liters of male urine each day was not easy, however, especially for a proud girl like herself who had a sterling reputation at school. What was worse, the only man in her house was her twin brother Greg. Brothers and fathers are a convenient but embarrassing source of urine for a modern woman.

On the morning of the first day that she'd resolved to adopt the diet, she walked down to the family kitchen in her green plaid skirt with thigh highs and white blouse, looking every bit the prim class president she was. Greg was at the table eating a pop tart.

"Breakfast of champions huh?" she asked, making herself bland oatmeal and fruit, the proscribed breakfast on this new diet.

"You know it," Greg said. "Hey what's with that glass?"

Shelby had sat down at the table with her plate of oatmeal and a clear drinking glass labelled like a measuring up to 500 milliliters. It was empty and did look rather strange on the breakfast table.

"It's for conveniently measuring urine quantities," Shelby said casually.

"Oh, naturally, " Greg said, rolling his eyes. "Did I ever tell you you're a fucking weirdo?"

"Don't be crude," Shelby said, "Go ahead and fill it with your urine, Greg."

"Oh I'm the crude one?" he asked, "You could have warned me you were getting on this diet, although I should have figured. You never met a bandwagon you didn't want to jump on, did you?"

Greg was wearing jeans and a flannel shirt over a white T-shirt, hardly being one to follow any trend whatsoever. Shelby just glared at her brother, having no patience for his usual sarcasm.

"Fiiine," he said, "This is the dumbest fad diet yet though. Even worse than the one where you could only eat grapefruit and cucumbers."

"This has been scientifically verified to work you know," she said, "Don't you believe in science?"

"Oh of course," Greg said, taking the cup. It was quite large for a drinking glass. "You know, you could have told me. I already took my morning leak when I woke up. I'm not sure how much I've got in the tank now but I guess we're about to find out huh?"

He stood up, unzipped, and pulled out his penis. Shelby, being a prim and proper girl, had never seen her brother's penis, or any penis. She tried to maintain serenely calm. This was just a diet, the biological aspect was unfortunate but unavoidable.

Greg lowered his cock into the glass.

"Come on, do it!" she said.

"I'm trying! Peeing on demand is hard, especially with your sister watching," Greg said in annoyance. Finally his flow began, hitting the bottom of the glass with an embarrassingly loud hollow splashing sound. Slowly the urine began to fill the glass with a more satisfying sound. Greg shook out the last few drops then offered the glass to his sister. "150 milliliters of hot Greg urine," he said.

"That's all? I need 2 liters today!" Shelby pouted. She took the glass and pressed it to her lips, taking the first mouthful of hot, bitter piss and making herself swallow. Her nose twitched as she **** the liquid down. "Fucking disgusting," she whined.

"You're the one who wanted to do it!" Greg said, laughing, "How are you gonna drink 2 liters when you can't even get down a mouthful?"

Shelby glared at her brother, then began drinking again. She'd already drank cabbage juice and kale smoothies in the name of fad diets, urine was only a little bit more gross. The nasty liquid filled her mouth and she swallowed mouthful after mouthful after her brother's hot urine until the glass was empty.

"There!" she said, "See?"

"Congrats, you just drank a glass full of my pee," Greg said sarcastically to his sister. He tucked his cock back into his pants and she gave him the middle finger.

"I'll be expecting all of your urine from now on, Greg," she said. "Now let's go to school."