"Oh fuck, that feels good," Jennie moaned as Joe's hands slid down her back.
"Is that getting it?" Joe asked.
"Maybe. I don't know. I can still feel it in my middle back."
Joe and Jennie had been swimming on this hot summer day for the last hour. They both had the day off from their respective summer jobs, and they needed the break. Joe had been rushing from the convenience store to baseball practice every day, and Jennie had worked a whole week without a day off at the video store. She usually didn't mind so much, as she would need the money for books in the fall. The campus stores weren't cheap, and the used bookstores weren't much better. Joe was trying to save up money for the start of his freshman year at college next year, but figured most of it was going to be spent on the prom this year. He was desperately trying to get into Wendy Yost's jeans, but so far had no luck. He figured a nice night of wining and dining might lead to some sixty-nining.
Their parents were out of town, gone for a visit to their Aunt Andrea's place in Chicago. They both decided at breakfast that morning to do nothing but laze around the house all day, swim now and then, and watch Iron Chef together later that night.
However, while swimming, Jennie got a tight knot in her back. It was bad enough that Joe helped her out of the pool, for fear that his sister would fall over. He laid her down on a beach towel, hot from the July sun, and started to knead at her back after she asked him to help get it out. Joe's strong catcher's hands soon rubbed rough on Jennie's soft back though, and she nearly crawled away from him in pain.
"Shit, Joe! You're givin' me an Indian burn!"
"Sorry!" Joe blurted. "I didn't...Hand me that oil."
"Good idea," Jennie agreed, and handed Joe the bottle of tanning oil.
The oil was hot in Joe's hands and Jennie turned her head to her left and let out a deep breath as her brother's hands, all slippery and warm, slid down her strong back.
"Aaaaah!" She winced, baring her teeth.
"Is that it?" Joe asked, pressing deeper into the knot just under her bikini strap.
"Yes. Fuck, that hurts."
"You want me to stop?"
"No, it's a good hurt." Jennie chuckled. "Here." She folded her arms behind her back and untied her dark green bikini top, revealing the final inch of her spine to Joe's slippery hands. Joe sunk his thumbs into her hard muscles, making little fishhooks with them and drawing the tension further away from her spine.
That's when he noticed the throbbing under his swim trunks. They were still damp, but quickly drying in the July heat. His cock was growing by the second as he straddled over his sisters thighs and worked his fingers into her back. The base of his cock was fitting quite nicely between her ass cheeks, he noticed. He wondered what she was thinking. He wondered what he was doing! His heart was racing and the sweat on his forehead seemed to be coming out of hundreds of little faucets behind his hairline. She had to notice. How could she not?
His hands moved to her lower back, brushing along the top of his bikini bottoms and barely brushing her hips. He looked over his sister's ass for a good long while as he pushed his thumbs into her sacrum. His eyes roamed down her thighs and then back up her ribs, trying to catch a peek at her breasts.
"You wanna try and pop my back?" Jennie asked.
"Yeah, sure," Joe squeaked.
