It was yet another miserably hot day at the cabin in the woods. Record high heat and a drought had made this annual family vacation an abysmal failure. The ground was cracked and on the rare occasion that a hot wind blew, it only managed to kick dust up in the air. Normally lush green trees hung limply with dying brown leaves.

Jake sat in the shade of the porch and stared into the woods. He was quiet boy, usually hanging out with the school nerds. He was average height, a bit stocky, but not fat. His dark brown hair was always a mess, practically untamable by a brush. His eyes were also dark brown, open and easy to read. He could be energetic but just as prone to laziness.

The heat had long ago sapped any energy he might have mustered to go exploring. The lake looked deceptively inviting, but the scalding sun made even a quick wet frolic into a disappointment. So he sat in the shade and dreamed of being home with his friends.

He sighed and tried to find something more constructive to think about, something that would let his mind wander and pass the time until the sun set and maybe a slightly cooler breeze would bring some relief. He closed his eyes and soon imagined he was all alone with Cindy.

Jake had known Cindy since kindergarten and they had just finished their first year in high school together. He had liked her for years, but never said a word because he did not want to spoil their friendship. She had long blonde hair and the prettiest blue eyes he had ever seen. They would sparkle when she laughed. She laughed a lot and he imagined that was what it was like for angels to sing. Her perfectly defined lips were soft and red. He had kissed her once, on last Valentine's Day, when she dared him, and he still remembered the softness of her lips on his.

Cindy was a bit of an athlete and had the slender, hard body of a serious runner. Her breasts were rather small. She once confided to him that her nipples were terribly sensitive which explained why her nipples were so hard and erect most of the time. Recently she had begun to develop real curves to her figure. She complained her hips were getting too big, but truthfully she was still quite petite. Her butt was firm and sculpted like a perfect inverted heart. She was proudest of her legs and she enjoyed wearing short skirts or tiny gym shorts to show them off.

Just imagining being alone with her, his arm around her waist, and their bodies touching, aroused him. Being trapped in the isolated cabin with his family had kept him from finding any sexual relief. The intense heat kept him too close to the house to comfortably masturbate. As he laid there with his erection straining at his jeans and his balls throbbing for discharge, Jake decided that fantasizing about Cindy had been a bad idea. He grimaced at the discomfort caused his cock straining to tear through his jeans.

He reached down to adjust himself, hoping to ease the strain. He tugged on the front of his jeans and nudged his hard-on around until the ache was lessened somewhat. When he adjusted his balls he realized he would have find a way to masturbate somewhere or they would be too sensitive to tolerate.

"Wow, what's got you all excited, little brother?"

Jake's heart skipped a beat and he sat up suddenly, crushing his balls. He winced and groaned when he realized his older sister, Amy was standing by the steps. She was staring intently at his groin. There was no way he could hide his arousal so he did not even try.

"None of your business," he retorted.

"Well, that's a big boner. She'll be a lucky girl someday." She leaned against the porch rail and smirked at him. He was not sure if she was serious or pulling his leg. And why was she interested in his erection anyway?

"What makes you think she isn't already," he replied defiantly.

She laughed mockingly. "Oh, please. I doubt you've even seen a pair a tits, let alone touched any." Which was only partly true. He had snuck peaks at Amy's tits at home a few times just out of curiosity.

Amy was two years older than Jake and would be a senior this fall. They were about the same height, but she was still smaller. While Cindy was athletic and thin, Amy was more voluptuous. She had short brown hair with some golden highlights that the recent summer sun had brought out. Her eyes were deep brown and somehow always managed to conceal what she was really thinking. In fifteen years Jake never had figured her out. Her short hair exposed a long, delicate neck that he suddenly found entirely too intriguing. Her breasts were much larger than Cindy's and bounced and jiggled when she got excited. He noticed now that she was wearing a plain white t-shirt and that sweat stains had made portions of it nearly sheer. In fact, now that he was looking, he could see the dark circles of her areolas and realized that her erect nipples stretched the thin fabric outwards.

His cock throbbed with excitement as he took more notice of his sister. She wore denim cut-offs that had been her favorites last year. They were rather tight and much shorter on her this year. Her legs were long and glistened with sweat, leading up to feminine hips and a firm, round ass. His balls tightened and the ache spread throughout his groin.

She giggled and Jake struggled to his feet. "I swear that thing must be alive. I think it was twitching." She covered her mouth when she laughed.

"Yeah, whatever," Jake replied and stormed off. He headed around to the back of the cabin and found a fallen tree in some shade and sat down. A moment later Amy clambered around as well.

"Really? Come to pester me some more?" He was pissed. He was embarrassed. And he desperately needed to jack off.

"Sorry, didn't mean to hit a nerve back there." She grimaced and squatted down right across from him. "This heat is just driving me crazy is all. I wish mom and dad would hurry back with dinner and some cold sodas."

Jake leaned back against a crooked limb. "Maybe we can convince them to call off this stupid vacation and go back home to some air conditioning. This heat sucks."

Amy nodded in agreement and picked at few a twigs. "I doubt they will. You know how stubborn they are. They'll want to tough it out like it was some great adventure or something."

Jake shrugged in defeat. Then he noticed his sister was squatting spread legged across from him. He stared at the shimmering expanse of skin of her inner thighs that lead to her shadowy crotch. The narrow seam of her cut-offs was pulled tight against her mound, barely concealing her shaved pussy. In addition to her not bothering to wear a bra, it was obvious she had not put on panties either.

"What? Is there a bug on me or something?" Amy jumped up and started wiggling and wiping away imagined bugs.

Jake chuckled. The first time he had laughed during the hot, miserable trip. He could not help but admire the way his sister's tits bounced as she scrambled away from the imaginary bugs.

"There was no bug, silly." He replied with a grin.

Amy slowly stopped her anti-bug dance and regarded her little brother. His renewed arousal was rather obvious. "What were you staring at then," she asked suspiciously as she realized where he had been looking.

"Nothing!" Jake sat up defensively "I was just thinking is all."

"Uh-huh. You got a hard-on again," Amy replied and pointed at Jake's swollen member. "Were you perving on your sister?" She grinned mischievously.

"Well, um, no. I mean..." Jake floundered for an excuse.

Amy put her fists on her hips and stood dominantly with her feet apart. "You know you can never lie to me. Come on tell the truth. Were you just perving on me?"

Jake slumped back against the tree. His erection suddenly deflated and his balls sagged with defeat. "Yeah, I guess so. Sorry." He shrugged his shoulders. He just hoped she would not tell their parents. "I mean you were checking out my package and all earlier. So I um, well."

Amy grunted and smiled. "Yeah, well guess you're right. Serves me right for perving on my little brother." She walked over to the tree and sat beside Jake. "So how much did you see?" She threw an arm around her brother and grabbed him in a head lock.

Usually, Jake hated when Amy head locked him. But this time she smashed his face against her breasts. He realized just how firm her tits were, and yet they were still so very soft and yielding. He tried to reply but found her nipple jammed into his mouth. He opened and closed his mouth to speak but only managed a garbled grunt as he suckled her. Amy shuddered and let him loose.

"Wow! That, um felt ... wow," she said and hopped off the tree.

Jake stared at her wide-eyed. "Yeah. Wow."

"You ever, um, do that with a girl before?" She held her hands over her breasts, trying to subdue the tingles that swept though her.

Jake shook his head. "No. I mean I have dreamed of it. But no." He jumped down from the tree and stood beside his sister. No matter how hard he tried to will it away, his cock was now quite rigid.

Amy looked at him from the corner of her eye. "Yeah, me either. Felt good though." Then she raced off through the woods.