Any hint of being turned on left Dax immediately as he ran up to his room, overcome by absolute embarrassment.  What the fuck was he thinking?  She asked him to put lotion on her back and that was it; any more intent than that was purely in his mind.  It had to be, right?  RIGHT?!?  He went from never even looking at his sister in a sexual way earlier in the week, to actually trying to feel her asshole today.  

But, fuck, he thought to himself, that was fucking hot, the way her ass looked, how she raised it in the air, feeling her side-boob, slipping my finger under her suit...  At those thoughts, he felt a tingle and realized he was getting hard again, his horniness returning.  Despite his embarrassment, despite his shame, he reached back into his shorts.  Already half-hard, his phone startled him again.  It was a message from Beth.

Hey, look I'm sorry I shouldn't have jumped up like that.  Let me still make you lunch, let's just put that past us, ok?  Give me a few to shower and meet me downstairs, she wrote him.

He hesitated, but eventually replied back with a quick "ok."  He walked over and looked out his window, noticing she was gone at the same time he heard the shower turn on.  He couldn't help but think about her in the shower, but not wanting to be uncomfortable when he went down for lunch he turned on his video game console and played some games to occupy his mind.  She knocked on his door about fifteen minutes later and told him she was heading down.

When he turned the corner into the kitchen he saw her bent over, looking in the fridge, in a short summer dress (was that a new dress?).  It was an off-white color with small pink and purple flowers on it, and peeking from underneath it was her ass.  Instead of being bare though, he noticed she had on bright pink panties.  She must have not heard him, because she kept digging in the fridge.  On the island, she already had a glass and a paper plate.

He shuffled uncomfortably, but he stood there and watched her.  Her ass was swaying back and forth as she searched the shelves, grabbing supplies as she went.  He was mesmerized; he had never seen panties quite like those before and he found them extremely hot.  The back came up in between in her cheeks a little bit, but as it got near the top it fanned back out like regular panties.  However, these were also sheer, and she was now bent over so far he could actually see the dark spot which must be her hole.  

Beth knew he was there, of course, and she took one more deep bend before standing up and turning around.  She was glad to see his expression got even more surprised as she turned around; the dress she was wearing was fairly tight around her chest, had a very low V-neckline, was made out of a very thin; slightly sheer material, and she wasn't wearing a bra.  She didn't need to look down to know her nipples were hard too, cold from the cold fridge air.

She strode over to the island counter, loving the way she could feel her breasts freely bounce as she walked, and set down all of the sandwich supplies.  She smiled up at him and without a word began to make him lunch.

He walked over and sat on the stool on the other side of the counter from where she was at, and while he tried to focus on other things, his eyes kept going back to her chest.  Not only were her nipples hard, but he could clearly make out their darker color in her light dress as well.  If that wasn't bad enough, every time she leaned down he could see nearly her whole breast.  All the while, she just continued to make his lunch, looking up now and then with a smile.

"Would you like some chips too?  A soda?" she said, catching him off guard.

"Sure...yeah sure both," he replied.

"Ice?"

"Okay."

She walked over to the cabinet where the chips were and as she reached up for them her dress was raised above her ass.  In fact, it was so short that she was pretty sure most of her ass was now showing, and at this realization, she smiled to herself.  Am I taking this too far? she thought to herself.  As she looked back at him with chips in hand, the expression on his face gave her the answer she needed.  She didn't care if she was pushing him too far; this was way too much fun.

As Dax took the chip-clip off the chips and began to pour himself some, he watched Beth as she walked over and got him a soda can from another cabinet.  As she was getting him some ice from the icemaker in the fridge, a piece dropped on the floor, and he couldn't help but stare as she bent down fully at the waist to pick it up.  This time, not only could he make out the dark spot that was her hole, he could also see the bottom of her pussy and his eyes were glued to the way her panties contoured her lips.  What really caught his attention, though, was the small wet spot where the sheer panties turned to lace.

He shifted uneasily in his seat and began to eat as she slid his drink to him across the island.  He smiled and thanked her, not saying a word.  She began to put the sandwich supplies away, and just as she did when she got them out she paid no mind to the fact that her ass was showing.  After she was done she went and sat in the recliner on the edge of the living room, pulling her knees up to her chest as she read a book.  This gave him a clear view of her ass cheeks meeting her thighs, and he noticed her wet spot seemed to be even darker now.

She put her book down, jiggled the recliner handle, and then looked up at him.  "Would you mind, sorry, this handle seems to be stuck...could you give it a shot?"  

His heart leapt from his chest because he knew how hard he was right now, but if he just sat there and didn't help, he'd come off looking just as dumb.  So he spun off the stool so he was facing away from her and before he turned around he adjusted himself.  He knew it was still showing a bit, but at least he wasn't sticking straight out.

He walked over to her, and just as her breasts were bouncing before, so was his dick now.  He could feel it moving out of place and it seemed like with every step it stuck out further and further.  By the time he got to her, it was now poking out at about a forty-five-degree angle halfway down his thigh.  He bent down next to the chair to try the handle, and at the same time took the opportunity to adjust himself again.  Of course, the handle worked just fine...just as Beth knew it would. 

He tucked himself in his waistband before he stood up again and he headed back upstairs, not even cleaning up his plate from lunch.  About halfway up the stairs he heard her call for him.

"You're welcome for lunch!" she said, "I see you left your plate to thank me?"

Shit, he murmured to himself.  He ran back downstairs and she was already standing by the trashcan, holding his plate.

"That's okay, don't worry about it, I'll get it.  I said I'd make lunch, that includes cleaning up, right?" she said.  She then turned around, dumped his plate in the can, and then bent over to tie the now-full bag.  This time, though, she was bending over directly in front of him and it gave him the same view he'd have if he was fucking her from behind.  Naturally, that's where his mind went and he started to imagine doing to her what he'd seen in so many porn movies.  

As she stood up her ass brushed against his crotch, and with a quick turn, she was headed out back to put the trash in the big can.  He watched her walk away before heading back upstairs, his mind replaying what had just happened over and over.  He sat at his laptop, and wanting to get his mind off his sister he decided to finish up the introductory essays he had started earlier in the week.  He flipped open his laptop and began to work, but it was impossible to think of anything else.

While he had never gotten fully soft after going upstairs, he was now hard as a rock again as he thought about that growing wet spot on her panties.  From watching porn and reading stories, he knew what that meant, and mixed with what he just saw, it made it impossible to keep his hands off his cock.  This time instead of sliding his hands down his pants, he pulled his cock out and began to stroke it.  Being a virgin, he didn't really have a grasp on how important her being so wet was, but the idea still turned him on beyond belief.

Beth knew, though, and as she sat in her room next to his, she already had her legs spread and her panties off.  She began to run the tip of her finger down her slit, and she was so wet that she knew all she had to do was apply a little bit of pressure and she'd slide right inside.  She looked over at her laptop, and in a daze of horniness, she began to get impatient and decided to send him a message.

I know you were hard downstairs, are you pleasuring yourself right now? she typed...and hit send.

He stared at her message, embarrassed and ashamed, his cock beginning to shrink.  Another message popped up from her...

Because...I am.

He was rock hard again within seconds...