"I'll show you mine..." (closed)

Carly knocked lightly on her brother's door, waited for what sounded like a grunt of permission, opened the door, and stuck her head inside. Her fraternal twin was laid back on his bed, pillows piled behind him, knees up, with his tablet resting on his thighs as he tapped and swiped at its screen.

"Busy?" she asked, wondering whether he was playing a game, catching up on his social media, or watching porn. She smiled, imagining the recently turned 18 year old was probably doing the latter. Isn't that what all teenage boys did in their bedrooms with their electronic devices? She didn't wait for a response to her question, instead simply entering, closing the door behind her, and leaning back against it. "Hey ... so ... about the other day..."

She didn't have to say anything more than that for him to know the day about which she was talking. Carly had thought she was alone in the house and was changing when her brother stepped into her open bedroom door and saw a little more of Carly than she would have preferred. She'd been naked, first slipping on her panties with her back to the door, then turning as she donned her top and adjusted it about her shoulders and smallish but pert titties; and only then did she notice her brother stepping away from the doorway. He said nothing; she said nothing; but Carly knew he'd seen her naked or semi-naked because for the next three days he'd blushed every time they came into view of one another.

"So ... I'm thinking..." she continued, a devilish smirk on her face. "Since you got to see me naked ... maybe I should get to see you naked, too."

Chris had been watching porn on his tablet, just as Carly had imagined. He'd had his Bluetooth headphones on and hadn't heard her knock. It was the movement of the opening door that had got him quickly moving: he'd muted the sound of the screaming woman and grunting man; he shut down the window; he'd tossed the tablet aside; and he'd slipped off the headphones to smile to his twin. But Chris kept his knees bent and elevated. He had a raging hard-on that would have lifted the blankets noticeably otherwise.

Then Carly dropped a bombshell. His eyes widened and he felt his face go white with shock. He hadn't realized that his sister had seen him in the doorway that day. She hadn't said anything to him about it for, what, three days, four? And now she was telling him that she should get to see him naked!

"What ... I don't ... I mean..."

Chris was at a total loss. What was he supposed to say? He hadn't meant to spy his sister in a state of undress, obviously. He wasn't sorry he had either. Obviously. My god, she was incredible! Tight, fit, petite body. He stepped into the doorway to ask if she knew where their folks were. And there she was, back to him, stark naked! His eyes had widened, as they were now. And his cock had hardened, as it was now. And he'd hurried away when he feared discovery, just as he wished he could now.

"What are you talking about?" Chris tried, feigning ignorance. "When did I see you naked?"

He ignored the part about her wanting to see him naked, too. Well, he didn't ignore it. He couldn't get it out of him mind that Carly had asked such a thing. Why would she want to see him naked? Was she looking for the same kind of visual stimulation that had led Chris to masturbating four or five times a day every day since that day? Or was this just a sibling revenge kind of thing?

Carly's lips widened in a smile as she pushed away from the door and padded barefoot across the carpet to drop on the edge of her brother's bed. She was wearing a more substantial tee shirt this evening, but the thin cotton couldn't hide Carly's ever-hard nipples, and down below she wore only panties which wasn't that uncommon for the teen.
The crotch of the latter were likely on display to her brother as she lifted one knee up under the bed, bending it until the soul of that foot was pressed against the inside of her other knee.

“Come on,” she said in that urging voice of hers, the one she used when she knew he was telling a lie or avoiding a chore or one of the other many things he did when he shouldn't have been. “You know what I'm talking about. The other day when you stood in my doorway and watched me dress ... watched me when I was naked.”

She glanced down at his fit teenage boy’s chest, then back up to his eyes and asked with a devilish smirk, “Tell me, how long were you standing there? How much of me did you see? Everything…?”