It was the middle of the afternoon on a weekday. Dan walked into the living room and found his little sister Susan sitting on the sofa. She wasn't really little anymore. But she was wearing her girlish reading glasses which Dan always thought made her look younger than her eighteen years.
It wasn't what she was wearing that startled Dan. It was what she wasn't wearing. She had on her cute reading glasses and a front-buttoned shirt. That was all. Her panties were wadded next to her on the sofa. She was busy rubbing her bare pussy when she noticed Dan standing across the room.
"SHIT! SHIT! What are you doing here?" She grabbed her panties and put them on her lap. She then folded her hands in her lap. She still looked pretty naked.
"Big mechanical problem. Boss sent us all home early. Looks like you're having a little fun in the afternoon. Mom's gone I take it."
"Stop. Leave. I need to get dressed".
"Dan reached over and grabbed a book off the bookshelf. "No, I think I'll sit here and read for a while." He began perusing the book. "You can go back to whatever you were doing."
"Very funny. My pants are in the other room. Leave so I can get them without walking past you naked."
Dan sat in a nearby chair. "I'm good here. Just pretend I'm not here."
"You think I'm going to let you sit and watch while I finger my pussy?"
"Oh. Is that what you were doing? Well it looks like a lovely pussy from here -- what I can see of it. I don't blame you for fingering it."
"You are such a dick of a brother. And a pervert." She put her head back and closed her eyes. "Arrrgh!"
Dan continued to read.
"Do you really want to watch me put my panties on and then walk right past you?"
"You don't have to put them on for me."
"Fuck you. Just go get my pants. They're in my bedroom. OK?"
"Well I'm not comfortable going into your bedroom when you're not there. Besides, it was your decision to sit out here in only your panties. What's changed your mind? And if I may point out, you even took the panties off."
Susan just stared at him and shook her head. "Did I mention that you are really a dick of a brother?"
Dan just smiled and returned to his book.
Susan sat. She looked around the room. She looked at Dan. She considered her options. She thought about how good she was feeling just before Dan showed up.
Susan looked to see if Dan was paying attention. She put one hand on her breast over her shirt, and the other down between her legs. She began massaging. Dan looked up from the book. Susan stuck her tongue out at him and continued to rub herself.
"Well Susan, you are a surprise."
"You're still a dick of a brother. But I was really enjoying myself when you interrupted me."
"You could have put up a sign -- 'Do Not Enter, Little Sister Masturbating'."
Susan ignored him. She put the underwear back on the sofa, spread her legs a bit more and started to masturbate. She snuck a glance at Dan. He was looking at her.
"You're just a perverted big brother who likes to watch his little sister masturbate." She continued to rub.
"I admit it. I'm very much liking this. It's very sexy with the reading glasses."
"So you like to watch your sister finger her pussy?" Susan was clearly starting to allow herself to become aroused.
"Yes, I like to watch while you finger your pussy. Do you like me watching you?"
Susan slid two of her fingers into her opening and began stroking. "Hmmm. Maybe I do like you watching me. I'll never tell. Tell me what you like about it." She started to move her hips in a rhythm.
Dan put the book on the floor. "It turns me on. You look so sexy."
"How much does it turn you on? Is your dick getting hard?"
