It's Bea, the youngest sister

The youngest sister, Bea, was standing there, one hand covering her mouth. She wore an extra-large tee shirt and carpenter pants.

Judy said, "Come on, sis. Come get your birthday fuck!"

Chuck asked, "Birthday fuck?"

"Huh?" Bea said. She stood dazed like a doe in headlights, her eyes enormous.

"She just had her eighteenth birthday last week," Sandy explained.

"I thought she would be seventeen until some time after school started," Chuck said.

"Oh, she got bored with school one year and didn't pass forward. She was too smart for that school," Judy explains. "Come on, Bea. It'll be fun. And Chuck is good."

"Mm-hmm, very good," said Sandy, a wry smile on her lips.

Sandy was the first to get up, but Judy wasn't far behind. They walked to Bea, who couldn't move from the doorway. They led her into the room. Bea had her arms crossed in front of her, defensively. Sandy and Judy each took a hand, and while whispering in her ear, disentangled her arms. Chuck could see Bea's nipples poking into her loose tee shirt. As resistant as she appeared, she was still turned on.

"Come here. I won't bite, unless you want me too," Chuck said in a calm but sexy voice. His cock surged back to stiffness thinking about Bea naked. Her innocence was very alluring and sexy. Did her naiveté mean she was a virgin?

"Is this your first time, Bea?" Judy asked before Chuck could open his mouth.

The youngest sister focused on Judy and shook her head. She tried to speak twice before she finally got out, "No. I'm not a virgin."

"All right!" Sandy exclaimed. "Our little geek girl got laid! Who was it?"

"Danny Giardino said he liked my glasses. We made out in the bio lab and then we fucked. He was a virgin too."

"Danny the nerd? Was this a science experiment?" Judy chuckled, and Sandy joined in.

"Well, yes. Kind of. We wanted to see what it was like. He didn't make me orgasm, but he shot all over my belly. Very messy." She wrinkled her brow a bit.

"Then you definitely need to fuck Chuck here. He'll make you come, won't you, Chuck?" Sandy said. She grinned at me and caressed my face.

"Bea, it would be my honor to show what sex is really about." Bea couldn't take her eyes off my johnson, sticking up in my lap.

"So, Bea, show him what you've got!" Judy said as she grabbed the hem of Bea's tee shirt. She lifted it as Sandy raised Bea's arms, running her fingers up Bea's skin. Judy completed the move over Bea's head. Bea stood in her white cotton bra. On her thin frame, her tits looked bigger than they would on someone with a bigger frame. Chuck thought they looked like C-cups.

"I don't know. What if he doesn't like me?" Bea said nervously.

"So far, you look beautiful, Bea. Let me see more." Chuck grinned at her.

"Here," was all Sandy said before she unsnapped the bra and let it fall.

Chuck wolf-whistled at her lovely breasts, full and round with thick nipples and dark red areolas. This seemed to put Bea in a good mood. She smiled shyly back at him.

Judy was now knealing at Bea's feet, taking off her shoes and then undoing her carpenter pants. She pulled them down, and Sandy gave Bea an arm to steady herself as Bea stepped out of the pants.

Chuck admired her legs, long and smooth. Standing there in just her white cotton granny panties, she had quite a nice body. "Wow! You look great, Bea. Why do you cover up this lovely body of yours? You should show it off," Chuck said.

Bea blushed and said, "Oh, you're just saying that."

"No, he's not, Bea," said Judy. "You are a beautiful girl."

"Yes," Sandy said. She took Bea's glasses off and pulled out the chop stick holding Bea's hair up. She ran her fingers through it to fluff it out. Without the geek glasses and with her hair down, Chuck thought Bea looked hot. He decided it was his time to act. He stood up and stepped toward her. She watched his cock bounce toward her. He leaned in to her. She didn't budge, so he met her lips and kissed her. He curled his arms around her and held her close to him. He darted his tongue out to lick her lips, and she opened them. He teased her tongue with his until she plunge her tongue into his mouth. His cock pressed into her belly, and he enjoyed the feel of her breasts squishing into his chest.