This is a work of fiction. The characters depicted are at least 18 years of age. Names, characters, businesses, places, events, and incidents are the products of imagination. Any resemblance to actual persons, living or dead, or actual events is purely coincidental. This is fantasy.
........................
Zac took a brutal pace up the mountain, and Alexa followed him with grim determination, hellbent on not showing any weakness. She kept her head up, not looking behind her, and took the same long strong strides Zac took. She was sure he was going fast on purpose. Just another game he was playing to show how strong he was, or some other silly point and she was confident that when he saw that she could do everything he could, he wouldn't feel so cocky.
By the third mile, her legs and arms aching, she finally remembered that Mark and Marie were behind them. When she turned around to check on him, he wasn't there, and neither was Marie.
"Zac!" she yelled ahead of her. "I can't see Marie and Mark!"
Zac stopped and turned to face her. His body rippled with sweat down his muscular arms, but he looked like he wasn't even breathing hard. He quickly scanned Alexa's supple body, paying particular attention to her bare legs. Though it was still unnerving to her because it was her sister's boyfriend, Alexa had started to get used to his gaze. After all, it wasn't so much different than when she was playing with her team.
"They couldn't keep up with you and me I guess." He said shrugging.
Alex blushed with pride.
Damn right
, she thought. They had practically flown up the hill.
"We better wait for them." Zac said. "Make sure that they're OK. Besides, I've got all Marie's water. She'll have to share with Mark."
Plucking a water bottle from the bag he was carrying Zac took a generous swig and handed it to Alexa. After she took a swig, Zac lifted his hand for a high five and she slapped it hard as both smiled at how awesome they were.
.........
"I need a break," Marie said. They had tried hard to stay with Alexa and Zac but after the first ten minutes they couldn't see them at all, and after the next ten, when they called for them, Zac and Alexa didn't answer. They had kept going as long as they could before Marie stopped by a log. To Mark, she didn't seem all that tired, but he didn't mind a break either.
Mark offered Marie a swig of his bottle and she took it. When she handed it back, he took another drink and the taste of her lips lingered on his own. Cherry, slick and sweet.
They sat silently for a few moments next to each other. The awkwardness palpable as the forest around sang its song. The log was slanted downward with the path, and Mark felt gravity pulling him towards his girlfriend's sister.
"It's hot," Marie said simply as she started peeling off her hoodie. Her shirt raised up with her sweater, and she made no attempt to hide herself. Evidently, Marie didn't like wearing a bra as Mark caught a quick peek at her perky breasts, and sharp perfect nipples underneath everything.
When the hoodie came off, Marie caught Mark staring at her chest. Setting the hoodie on the ground, she smiled warmly at him.
"You see something you like?" Marie said coquettishly.
"No. I...I just had something in my eye." Mark said, rubbing his eyes, trying to cover for himself, but quickly realizing how stupid the excuse was.
"You sure?" Marie said, tugging playfully up at her t-shirt, revealing her toned midriff.
Mark said nothing, mesmerized instead by Marie. He couldn't help but look at her and the nipples poking through her shirt.
"Don't worry Mark," Marie said, "I'm not a prude like Alexa is. I don't mind if you look."
"Alexa is not a prude." Mark said defensively, turning away for a moment before quickly turning back.
"Oh yeah, how would she feel if Zac saw what you just saw?" Marie said. She gripped her shirt lightly with both hands as she inched it higher. "Would she pull up her shirt like this. And give someone who's not her boyfriend a better look at these."
Marie pulled her shirt up and over her breasts and playfully wiggled her body.
Mesmerized, Mark stared. As she moved, he saw her small breasts move with her. The sight of her pink nipples were hypnotizing, and he couldn't help but wonder what they would taste like in his mouth. How could two sisters be so different? Marie's breasts were perfect dollops of creamy ice cream while Alexa's were large cantaloupes.
When he said nothing else, Marie finished her game by slipping her shirt all the way off and dropping it on top of her hoodie. She bounced up and down on the log coquettishly.
"Marie... You can't..." Mark said but his wide eyes and hardening cock told a different story.
"What's the matter Mark? Afraid Zac is going to come down the hill and see us."
"No." Mark said, anger and shame rushing to his head as he finally peeled his eyes away from her. "I just - Alexa."
"Oh I see. You're afraid I'll tell Alexa that you saw my itty-bitty titties?" Marie said in sing-song voice, bouncing up and down again.
"No. I mean, yes." Mark stammered.
"Well, if we're going to get caught, maybe we should do something worth getting caught over." Marie said, smiling. "Wanna touch them?"
............
"Maybe we should go down after them." Alexa said.
"Nah." Zac said. "They'll catch up eventually."
They stood there in awkward silence, the tension between them humid and thick.
"So, what were you and Mark up to in that tent?" Zac finally said.
Alexa narrowed her eyes at Zac. Why was he even asking? He had already guessed what they were doing, and she didn't want to elaborate. It wasn't something a good girl would say.
"Just changing," she said.
"Sure." Zac said rolling eyes.
"That was it!" Alex said defensively, "And if it was something else it's none of your business anyway."
Zac raised his arms to shield himself, "Hey, hey I got you! I was just wondering how vanilla you two are in the sheets. Now I know."
"Mark is going to be up here any minute." Alexa said.
"So? We're both adults here Alexa. You and Marie talk about sex don't you?"
Alexa wiggled her nose. Marie talked. Alexa listened mostly. It wasn't that she didn't want to talk about it. It was that her parents had taught her that this stuff was between partners and besides that, she wasn't going to talk about it with her sister's boyfriend alone. That just seemed... dangerous.
"Kind of, but its... not the same with you."
"Why don't you try me?" Zac said. "I've got a lot of experience you know."
Alexa considered this for a minute, ignoring his bragging. She shuffled her feet nervously in the silence as she came to realize that he was challenging her.
She wasn't someone who backed down easily.
"Do you and Mark ever get crazy?" Zac asked.
"Crazy like how?"
