Her brother Greg

Shelby lay in bed the next morning. It was Saturday and one of her rare days with no need to rush out of bed for school, volunteering engagement or some relative's baby shower. It felt so good to simply lay in bed for a once and not have to **** herself into action. 7:59 ticked by on her big digital clock and she indulgently didn't move. Then it was 8:30 and she was still relaxing under the covers.

She was, however, very thirsty. Greg hadn't been home at midnight and she'd given up waiting. Besides, she was sure he'd emptied his bladder into that urinal-mouthed Eleanor Landry anyway. She'd gone to bed without any more of her favorite drink since the car ride with Wei, which had been fun but was quite a while ago at this point. She got out her tablet and did some shopping from bed, finding the product Wei mentioned to her, called a GirlCork. What a silly name, but she bought two anyway. The idea of storing warm, nutritious urine inside her holes to drink later would be convenient, if humiliating. But she was already drinking urine from boys, how much lower did she really have to go?

After she purchased her order, her door creaked open and Greg wandered into her bedroom. Her brother was totally nude, which 6 months ago would have horrified her, but now she was glad to see him and his hopefully piss-filled bladder.

"Still in bed at 9 in the morning? What have you done with the real Shelby?" Greg teased.

"Shut up, even I can sleep in once in a while," Shelby said, still curled up in bed and feeling good even though her brother was naked and approaching her with a boner. "I hope you still have some pee left over for your sister." She didn't mention that other urinal's name aloud.

"I think I might have some," Greg said with a grin, and pulled the sheets off Shelby. She was naked under the covers.

"Hey!" she said, covering her breasts awkwardly.

"Awww come on, you get to see me naked," Greg said, grabbing her wrists and nudging her hands away.

"Get to? You come in naked whether I want to see you naked or not," Shelby whined, but didn't fight him as he exposed her body. She was actually wanting him to see how hot her body had gotten lately. With the urine diet, she was actually keeping on her healthy diet without binging on ice cream or other junk due to the stress and hunger, so her abs had tightened up and she looked downright sporty, but still had her huge boobs and butt. Greg looked her over and whistled. "Pervert," she said, laying there under him, not resisting anymore. "Now pee in my mouth."

Greg laughed. "Who's the pervert? Nevermind," he teased. He straddled her with his knees on either side of her shoulders, aiming his cock and Shelby's wide-open mouth. She was excited to get her brother's tasty morning piss, but nothing came out.

"It's easier to get started with my dick inside Eleanor's mouth," Greg said.

Shelby hissed at the mention of that girl's name, feeling instant competitiveness. "Fine, whatever," she said. Previously she hadn't let him go this far, it was too much like **** to the high-strung class president.

Greg smiled and leaned forward, pressing the head of his eight-inch cock into his sister's wide-open mouth. Greg thought of forcing her to give him a blowjob, he was certainly horny enough, but he decided it was more fun to see what he could talk her into doing.

"Lick the peehole," he said, "That will get the flow started maybe."

Shelby sighed, but then he felt his sister's prissy tongue licking his peehole. It almost tickled, and felt very good. He looked down at his high-strung sister as she had to lick a peehole to try to get some urine. This felt so good because of what a bitch she was most of the time.

Still no piss, though. "Try milking it with your lips maybe?" Greg thought sure this was too much, but instantly he felt his sister's soft lips wrapping around his shaft. She squeezed as best she could, and even licked his pisshole on her own. This was so close to a blowjob from his squeaky-clean sister, he was getting very horny.

"It's no good," he said, trying to keep a straight face, "The only way Eleanor makes me piss when it's like this is my fingering my ass. It stimulates my prostate or something, it's blocking my flow."

Greg thought surely this was too much, and Shelby did hesitate, but then he felt her soft hands on his ass cheeks, spreading him. His sister's lips were still wrapped around his rock-hard cock. She felt his proud sister's dainty finger against his anal entrance, then Shelby hesitantly pushed inside. Greg's prissy sister was fingering his ass!

Greg liked making girls finger his butt. It was mildly embarrassing for them and it made him feel really good, especially when it was a shy girl working his finger deep into his rectum. Shelby must have been very thirsty, he thought, she squished her finger deep inside his ass, as far as one finger could go, all the way to her hand. She wiggled it inside her brother's butt and her groaned.

"Okay," he said, "Open wide for my piss."

Shelby slid her lips over her brother's cock as she pulled back, then opened her mouth wide and kept rubbing her brother's prostate with her finger up his anus. Greg finally managed to start pissing, letting his hot golden liquid flow into his sister's urinal mouth. Greg filled her mouth like it was a bowl then let her drink his hot piss to catch up before filling it again. He was having so much peeing into his prim sister's mouth that he didn't notice she'd snapped out her phone and loaded the app to monitor his pee volume to make sure she got her daily 2 liters, but that was just like his perfectionist sister.

It was so sexy to watch his sister make herself swallow those mouthfuls of urine. He knew it had to taste nasty even if she'd gotten used to it. And she'd done such humiliating things just to get him to pee in her mouth in the first place. He loved this. When he only filled her mouth half-way with piss on the sixth try, she fingered his rectum to coax out the last more drops, then swallowed. She pulled her finger out of his butthole finally, and he rewarded her by slapping his hard cock across her lips, making a few more drops of pee shake off into her thirsty mouth.

"Suck it," he groaned softly, "For the last drops of pee, I mean."

"Okay," she said, smiling blissfully. She took her brother's cock in her mouth, trying to suck the pee out of him at first, but he was totally try, and she knew it. She kept sucking her brother's cock anyway, wrapping her lips around his shaft. Greg closed his eyes and groaned. His perfect sister, the unapproachable class president, was finally sucking her brother's cock. It was she who succumb to shameful **** first, not him. This was the best blowjob he'd ever felt. He wanted to fuck his sister's smug face roughly, but today he was so horny he could only last a minute before shooting a massive blast of sperm down Shelby's throat.

She milked his cum then he pulled his cock out of her tight mouth with a loud slurping noise.

"Uh, thanks for the piss," Shelby said, blushing awkwardly at how carried away she'd gotten.

"Any time, sis," Greg said. He could humiliate her another time. For now he just patted her head adoringly.