It had been a long day and Emma was tired. With the long commute from London back home she didn't walk back in through the door until 7 o' clock, but at least with her mother out for the evening and her brother Tom and dad John on an off-roading trip she had the house to herself. She wanted to take advantage of the final rays of evening sun and get outside in the sun to top up her tan. With no one around she could take full advantage and not wear her top -- tan lines were something she just couldn't stand. She walked upstairs to her room, and put her bag down on the desk. Standing in front of the mirror, she pulled off her heels, jeans and t-shirt, leaving her standing in just her blue bra and red g-string.
She admired her body in the mirror. She had been working out a lot lately, and she cold really see the results. Her hips had a very sexual curve to them, her thighs and calved were more toned, and her B-Cup breasts hadn't changed shape from the exercise. She pulled off the bra, her perfect sized nipples hardening in the cool air of her room. She turned to admire herself from all angles. Her ass looked great -- enough curve that it looked great in jeans without being big, and with the tiny diamante heart at the top, her g-string looked hot as it cut between her pert asscheeks. She didn't bother taking a top with her -- just her sun cream -- and walked downstairs to open the backdoor to the garden, making sure she moved the sun lounger to the left hand side, close to the wall, so that she wouldn't be overlooked by the neighbours.
At the same time Tom woke up. They'd had to postpone the off roading trip for a couple of days due to his dad having to go down to their holiday properties on the South Coast to fix a burst pipe. Blinking he stretched, rubbing his eyes as he looked out of the window. He almost double took when he saw his older sister lying on her back on the sun lounger wearing nothing more than a pair of sunglasses and a thong. He was looking down almost right on her from above, but he knew that as long as he didn't stand right against the window she would never be able to see into his darkened room from the bright outside. He was so close to her that he could even see the thin strip of pubic hair through her sheer g-string, and his cock instantly started stiffening in his boxers. As he watched, she reached for her sun cream, and started rubbing it into her exposed skin making sure she put plenty on her sensitive nipples. His 7 inch cock was rock hard, tenting the front of the boxers he'd fallen asleep in.
Absentmindedly he reached down and started rubbing it as he watched her lie back, putting in her headphones. He knew he'd have to do something about it, but why should he just jerk himself off when his sister was down there and looking so hot. He kept watching as she rolled over onto her front, exposing that tight little ass to him, and he knew it was the right time. Quickly, he changed out of his boxers and pulled on his swimming trunks, tying the drawstring to hide his erection as best he could. It wasn't perfect by any stretch of the imagination. When he looked down he could see the tip of his penis on display, and the outline of his shaft was glaringly obvious, but it would have to do. He walked downstairs and into the garden through the other doors. He wanted to sneak up on her before she realised he was there, so he was very careful as he walked over the grass, despite the fact she could barely hear anything thanks to the music in her ears.
He sat down on the lounger next to her, and she immediately rolled over in shock, trying to cover her nipples with her hands.
"Tom! Jesus, what the hell are you doing here."
She was looking around for something to cover herself with but there was nothing, and to make it worse she was sure that she could see a massive erection poking through the front of his trunks.
"Dad had to go sort something out so we had to postpone the trip. What are you doing out here dressed like that?"
His eyes wandered down and Emma blushed as she realised he could see her landing strip through her g-string. She rolled back onto her front.
"I thought I was home alone. Is there anything wrong with that?"
She knew it was wrong, but knowing that he had an erection while he stared at her dressed in so little was turning her on.
"Nothing at all. Don't stop just because I'm here."
"Well go and get me a bikini from my room then! I can't lie here dressed like this when you're here can I?!"
"Well I don't see why not. After all, it didn't stop you sunbathing topless when I was watching you earlier, so why should it matter if I'm here. It's nothing I haven't seen before."
"Yeah, when we were kids!"
"I don't see that it makes any difference. After all, we're both grown up now."
She knew she shouldn't, but she wanted to go along with this game and see where it took them.
"Well, if you're going to be out here too you can at least make yourself useful. Can you rub sun cream into my back?"
He nodded and smiled, reaching for the cream and straddling her from behind. Emma felt a little quiver go through her as she realised she was being straddled by her brother with his erection, wearing nothing but a tiny g-string to cover her modesty. He rubbed the cream slowly into her shoulders and back, working his way lower and lower. Subconsciously she felt herself letting her legs part slightly as he worked his way to the top of her G-string.
"Looks like you haven't done your ass yet. I'll get that for you too."
She said nothing which he took as consent, and started rubbing the cream over her cute ass. She felt her pussy getting wetter as he lifted her g-string slightly, rubbing the cream in underneath it around her waist. The string was so thin she knew that as he massaged her asscheeks he must be getting a full view of her tight asshole, but that only turned her on more. Finally he stopped and got off her, and she had to stifle a moan of frustration as he did. But then, as he pulled his trunks down to expose his hard on she wasn't frustrated at all. As though it was completely normal to be naked in front of her, he pulled over the other sun lounger and laid back.
"My turn now Emma. Start with my legs and make sure you don't miss anything."
"Um....ok"
She could hardly refuse after all. She picked up the bottle and knelt between his legs, trying not to start as his swollen dick bobbed enticingly in front of her. She rubbed the cream into his calves, then higher up this thighs. She was just stretching out her hand to take his cock in her hand when he stopped her.
"My shoulders next please."
She didn't need asking twice. She straddled his stomach, almost able to feel his dick touching her pussy through the thin fabric of her thong as she massaged his shoulders, her nipples rock hard underneath her, aching to be touched. His body was slippery from the sun cream and she couldn't resist, as she rubbed in the sun cream, letting her boobs slide over his chest, her erect nipples tingling from the sensation.
"Now, get back on your lounger. And remove that underwear. I'm naked anyway and its practically see through -- especially now you've got a little wet patch on the front."
Emma blushed. She hadn't realised that she had got so turned on that it was visible on the front of her thong. She lay back on her own lounger and removed the thong, exposing the thin strip of hair above her swollen pussy lips. Tom stood over her.
"Now, spread your legs over the arms of the chair."
She did as instructed, so aroused to be in front of her brother, both completely naked. She pulled her legs up and back, spreading herself completely and exposing her pussy and ass to him.
"Now I think I'd better make sure that all of you has enough sun cream."
He picked up the bottle of sun cream and shook it.
"Have you ever been fisted before Emma?"
She shook her head, almost panting in excitement.
