Vagina.

"Get this. We got the vagina,” he replied with his cock pressing strongly against the fabric of his pants.

"Great, so I can help you find that. Man, aren't we a pair, or what?" Rachel replied cheerfully. The two of them headed toward his desired section. For some reason, he couldn't find any books with diagrams of the male genitalia. He flipped through many books, unable to reach his goal and find an accurate diagram.

'Sheesh, they have books on everything else but this...' he thought to himself. He kept looking through the worn books until he found one with a cover that interested him. On the cover was a beautiful, young woman, half-naked, with her privates just barely hidden beneath her hands and a leaf. Her tits looked big, soft, and round, if only she were here, right in front of him, at least he would be able to release his sexual tension. The title read, 'Know Your Body'. It must be some book for young girls going through puberty, but he didn't care about the title, the picture was enough. His erection definitely was not fading now; his cock was harder and stiffer than it was before. He felt uncomfortable as he fidgeted around in the tight constraints of his pants. He worried about Rachel seeing his boner; the bulge was too damn noticeable.

As he struggled, he felt a soft, warm hand press against his shoulder. "So did ya find anything?” Rachel questioned him in her cute voice.

"No, how 'bout you?” he curiously replied.

"Nah, they got nothing.” She sighed.

"What am I gonna do?” she pondered.

"Why not ask the librarian?” he asked.

"Can't, she's not around,” she quickly answered.

"What to do, what to do?” she softly repeated to herself, as he glanced at her sexy tits. He hid his erection as much as possible, praying for it to go down, but Rachel was not helping. Her presence alone stimulated his body.

"Let’s go sit down,” he said, hoping for her to lead the way. Luckily, she did as he followed her back, staring as her round ass wagged side to side. He sat down next to her.

"Why don't you show me your ummmm...you know?” She says, anxiously awaiting his reply.

He honestly cannot believe his ears. "What!?” he replied without thinking, completely shocked.

"C'mon, in the name of research, that's all.” She nervously giggled while biting her nails.

"Well ... remember ... I need help with my work too,” he replied, staring hard at her luscious, full breasts. His penis begged to be released, so it was not a bad idea. He hoped that this would not just be for the sake of research.

"Well ... it'd only be fair if I let you see me too ... so in the name of research, let's do it!” she nervously joked.

"Where do you wanna do this?” he asked.

"In the girl’s washroom, on the second floor. It's always empty, especially at a time like this,” she quickly answered while looking at him with sparkling yet anxious eyes. He couldn't believe his luck; he was going to see this sexy, young girl in the nude. 'Could it possibly lead to more?’ he pondered to himself.

The two of them stood up and walked toward the library's exit.