They give her a choice ()

"Come on Shelbs," Greg said to our sister, "You can't get us rock hard then leave us to beat off."

"Yeah peeing into the class president's butt was the hottest thing ever!" Mike said.

Shelby stood there naked, the two erect boys between her and the passage to her bedroom. How did she keep ending up in situations like this? She could probably yell at them or scream for mom and Dad and get out of this, but that would be embarrassing. Besides, she wasn't that opposed to some sex, as long as she didn't go looking for it like a slut. If she was being **** into it then she'd done nothing wrong, right?

"So what's it gonna be Shelbs? Are you going to give it to us willingly?" her brother asked.

"Fine," she said with a sigh, "But only because you'd **** me if I didn't."

The boys giggled stupidly to each other. Greg reached between her legs, rubbing her smooth twat.

"Did you shave this for me?" he asked.

"Ew no," she said. Then she sat down on the futon, raised her feet up to rest them on the mattress, spreading her legs crudely and presenting her cunt to the horny boys. "I don't suppose you'll use condoms?" she asked.

"Nope," Mike said, pushing Greg aside and getting on top of Shelby. The chubby nerd leaned in and kissed Shelby on the lips, slobbering into her mouth in his attempt at foreplay. She didn't kiss him back, and in a moment he got bored of that and slid his six inch cock into her cunt. Luckily she was horny from their crude treatment of her and her pussy was soaking wet, so the penetration wasn't painful.

As he fucked her bareback, she became acutely aware of how bloated she was with at least a liter of the boys' hot piss corked in her ass. She could feel it sloshing around as Mike fucked her. Maybe she could have picked a better position than sitting with her legs spread, and she hoped the GirlCork held up, otherwise she was going to spew urine out her butt midway through sex.

"I can't believe I'm fucking the class president's vagina!" Mike said giddily, "You have amazing boobs, Shelby."

He fondled her fat tits and she glared at him, trying to look annoyed and not let any moans escape as she took his cock.

"Hurry up and cum, oh and don't shoot your sperm in her, I don't want sloppy seconds," Greg said crudely as he watched his sister get fucked on the futon.

Mike's cock pistoned in and out of Shelby's bald hole. She kept her legs spread wide so the nerd could use her for sex, feeling the urine in her ass move as her body rocked back and forth.

Mike barely managed to pull out in time, shooting his white sperm on Shelby's tummy. She felt like a slut, the boys were using her body to cum, but it wasn't her idea so it was okay.

Greg pushed Mike out of the way then took the same position over Shelby's body on the futon. Her brother's cock was much bigger, about eight and a half inches, and he was stroking it as he looked at her naked body.

"God you're sexy Shelby, if you dressed in slutty clothes you'd be the hottest girl in school," Greg said.

"But then I'd be a slut!" Shelby protested.

"She said naked with her legs spread wide waiting for her brother's cock," Greg said as he stepped toward her.

"Fuck you!" Shelby said, but had to laugh. Mike was cracking up behind Greg.

Her brother pushed his big cock into Shelby's wet hole. He pushed deep and she gave up on the pretense and let out a moan.

"I can't believe the class president has ****!" Mike said.

"Shut up, Mike," Greg said, fucking his sister lustily as she moaned under him. Mike was a pussy and stopped his joking around and just watched the brother/sister sex, leaning in to watch Greg's cock slide in and out of Shelby's wet hole. Shelby felt so stuffed, between her brother's big cock and her rectum full of hot piss. She'd never done something this slutty in her life.

Shelby had enough respect not to talk dirty, but she was moaning and gasping as her brother fucked her. She grabbed his chest and screamed out an orgasm, which made Greg smile with pride.

"I'm cumming too," he said with a loud groan.

"Please pull out!" Shelby said, looking at her brother desperately as he pushed his cock deep inside her cunt one last time.

"No can do, sis," Greg said, groaning as he shot his sperm deep in his sister's vagina.

He lay there for a moment in bliss, and Shelby was overwhelmed with her own pleasure too. She wiggled out from under her brother after a moment and hurried to the bathroom to wash out her brother's sperm before she got pregnant.