I have been staying at my parents' house since I lost my bartending job after the restaurant I worked at shut down for good two months ago. I've been pretty lethargic, sleeping most of the day and hanging out in a tiny little bedroom. I'm 26 and accustomed to having my own space. Suddenly having to share space with my mom, dad, and little sister was a big readjustment. To make matters worse, my sister Ava moved into my bedroom when I left the house five years ago, so I am stuck in her old one.

Ava just turned 18, and she's starting her senior year of high school. She has been home all summer just reading books and messing around on her phone. We keep to ourselves as much as we can in a 3 bedroom house, but end up spending quite a bit of time together. She is about 5'4" and has an athletic body, thanks to years of gymnastics.

Growing up, we weren't very close because of the age difference. Even though she's 18, I still look at her as my baby sister. She is a smart girl and does really well in school. She has a couple close girl friends, but she doesn't run around with the popular social circle of football players, cheerleaders and such. She isn't awkward, but she's relatively shy, and the party crowd doesn't really appeal to her.

We've spent a good amount of time discussing all the social movements, economic turmoil, and societal upheaval that has taken over the news cycle this summer. It's been kind of nice getting to know her as an adult. Especially with how bored I've been lately, having someone pleasant to talk to is comforting. She's not the little girl I always picture her as anymore. She's a smart, capable, and nice looking young woman. Her breasts aren't huge, but they are nice and perky, which seems to be the case with most gymnasts. She has a great ass, though. I was caught off guard the first time I noticed her curvy backside shaped by years in the gym. She wears leggings around the house most of the time, highlighting her best asset. She has had a couple boyfriends, but nothing serious. Being the homebody she is, I don't think she was too concerned with dating at the moment.

Last weekend, I needed to wash my favorite pair of sweats after spilling some wine on them. I only had a couple other things to throw in the load with them, so I asked Ava if she had any laundry she wanted to toss in with mine. She told me she did a load earlier that afternoon so I emptied my basket into the machine and adjusted the dial. Just before I closed the lid I heard her call from down the hallway.

"Hold on a second, please! I might as well wash this stuff," she said as I walked back towards her bedroom.

We met in the hallway and I saw she had changed into some lightweight purple pajama shorts and an old t-shirt. Her hair was braided in pigtails today and she looked like the shy, innocent girl I had always known. She thanked me as I reached out and took the clothes she wore earlier from her. As she turned around I noticed her shorts looked a size too small. They hugged her ample bum, and just barely covered the bottom of her cheeks.

I pulled my eyes away from her perfect rear end and walked back to the bathroom with the washing machine and dryer. In my hands were the yoga pants and halter top she wore earlier. As I tossed them in the washer, a pair of light purple panties fell on the floor. I reached down and picked up a lace trimmed thong. I was surprised my little sister wore sexy underwear. They weren't see through or anything, but they certainly weren't the cotton briefs I would have expected.

I pictured her wearing them and I felt my dick react. I brought them to my nose and smelled the crotch. I knew my sister was a cute girl, but a switch had just been flipped. I closed the bathroom door and closed my eyes as I slid my pants down a little and grabbed my dick. I stroked myself while sniffing Ava's panties. After only a minute I was about to explode, so I pulled the panties from my face and came inside the crotch. I tossed them in with the rest of it and started the machine.

I was thinking about her tight young body for the next couple hours as the laundry went through its cycle. When it was finished, I brought it all back to my room to fold. I placed the little thong on top of her pile and carried it to her room. Her door was cracked and I gently knocked and pushed the door open. She was lying down on her bed reading, but jumped up and took her clothes from me and put the pile on top of her dresser.

I asked her what she was reading as she got back in bed and looked her phone. She was now leaning against the headboard with her knees bent and hanging off to either side. I could clearly see the outline of her pussy lips through the thin material of her shorts. I said "goodnight," and went back to my room for the night.

The next morning I went in to wake her up for breakfast. I said her name a couple times, and she just rolled from her side to her back but didn't open her eyes. I tapped her shoulder, and she sighed but still kept them closed. Finally, I just grabbed the bedsheet covering her and pulled it off while she moaned in protest. I was shocked to see her shorts in a ball on the bed and her uncovered pussy in plain view. She didn't even move, so I assumed she didn't remember she had taken her shorts off. I snapped a picture of her for later, then I quickly grabbed the panties I jacked off into the day before. I walked back to the bed and tossed them so they landed on her lower belly. "Might wanna cover yourself up, sis," I told her and walked out of the room.

My cock was rock hard as I went back to my room and closed the door. Why was she not wearing her shorts? My imagination took over and I pictured her sliding her fingers in and out of that tight young pussy. I imagined her looking into my eyes as she played with herself, showing off for her big brother. I opened my phone and zoomed in on her plump pussy, covered only by a neatly trimmed patch of light brown pubic hair. I imagined I was in between her legs, licking up and down her gash as she said my name. I grabbed a tissue from my nightstand and came into it. I stood up to put my pants back on and walked out my room and down the stairs.

My parents were both on their way out the door for work, and I sat down alone at the kitchen table. I ate my bowl of cereal, looked through the news on my phone, then went upstairs to take a shower. I heard knocking at the door and my sister's voice from the hallway.

"How long will you be? I'm running late. I need to brush my teeth," she asked.

"I'll be out in ten minutes, then it's all you," I shouted back.

"I don't have ten minutes. I can't be late on the first day," she argued back.

"Then come brush your teeth. I tried to wake you up a while ago," I said.

She walked in and went to the sink. I could see through the clear shower curtain, but it was pretty blurry. She was wearing a skirt and spaghetti strap shirt, and I wondered if she was wearing those sexy panties I tossed at her earlier that morning. I pictured guys at school seeing up her skirt as she sat in class. I felt my cock getting hard as I lathered myself.

"Was it warm in your room last night?" I asked her.

"What do you mean?" came her reply.

"I mean you weren't wearing any shorts when I woke you up," I said smiling.

"Oh my God! I was so out of it this morning. You saw me naked?"

She sounded honestly surprised to hear this information.

"I didn't see your boobs," I told her, thoroughly enjoying myself.

"But, you saw my...?"

"I saw your pussy," I interrupted her.

My cock was completely hard. I had never said anything like that to her before. She continued brushing her teeth in silence. The tension in the room was palpable. I was enjoying it, but I decided to try to lighten the mood and said, "No big deal. I can handle seeing a naked girl."

"Well maybe I don't want my brother looking at my vagina," she shot back.

"Next time don't take your shorts off then," I called after her as she walked out of the bathroom.

I jacked myself to completion in the shower, got out and dried off. Ava had already left for school, and I couldn't stop thinking about our bathroom conversation. I was now alone in my house, and didn't bother putting any clothes on. I walked into my sister's room and opened up the top drawer of her dresser. Her bras and panties were lined up and folded neatly. I grabbed a bra and looked at the cup size. 34B. I tried to picture what her naked breasts looked like. I wondered how big her nipples were. She had some plain cotton panties and a few sexy looking ones. I grabbed one of the lacy ones and brought it up to my face. I was so horny. I went and grabbed my phone and sent a text to Ava.

"Sorry about earlier. I guess I would feel weird if I were you, too."

She replied quickly, "It's fine I guess. But it's weird knowing you've seen me naked."

"I have an idea," I wrote back.

"What's that?" She asked.

"If you see me naked are we even then?" I sent her.

"Haha. As if you'd show me," she said.

I took a selfie on my bed. My dick was hard and I held it in my hand My face and penis were clearly visible in the picture. My cock was about 7 inches hard usually, but it had to have been a half inch longer in this picture. I felt so dirty. I sent it to her. "There you go."

"Oh my god!" she replied. "Why do you have a boner?"

"I thought it would be rude if I wasn't hard after looking at your pussy," I said.

"Well, thanks, I guess. This is weird," she texted back.

"Send me a selfie? I barely even saw you earlier," I pushed my luck.

A few minutes later I received a picture of her sitting on the toilet with her legs spread. She had her panties pulled to the side and her inner folds were clearly visible. Her slit looked wet and I grabbed my cock. Her face was in the picture, too. She was sticking her tongue out at me.

"Looks delicious. Can I taste after school?" I texted back.

"You want to eat your little sister out, you freak?!" came her reply.

"Come to my room after school and see!" I said.

I lay in bed going back and forth between the two pictures I had of my little sister, stroking myself but trying not to climax. I got bold and went to my bedroom door and opened it, then got completely naked and went back to what I was doing.

At 3:01 PM I heard the front door unlock. It was a half hour before she usually came home, but I didn't think much of it, and kept playing with my cock. It was the moment of truth. Was she actually going to let me lick her pussy? That remained to be seen, but I was gonna show her my cock either way. My heart was pounding at least as hard as my hand was pounding my cock. I heard footsteps walking up the stairs. My bedroom door was wide open, and my eyes were almost completely closed, but my right eye squinted slightly open to see her reaction when she saw me.

What happened next almost made my head explode. I was engaged in the kinkiest, most forbidden act of my life. I had been trying to hook up with my little sister all day, and wasn't expecting anything to happen that would minimize the craziness of that, but it did. My mom came around the corner of the hallway, and my eyes immediately opened wide as she gasped and covered her mouth with her hand. I tried to cover myself up, but she got a clear look at what was going on. She may not have seen the pictures I had open on my phone, but there's no way she didn't see the pair of Ava's panties draped over my thigh while I held my boner in my hand.

She turned and ran down the stairs as I quickly threw some sweatpants and a t-shirt on and chased after her.

"Mom, I'm sorry. I didn't expect you home," I pleaded in absolute terror.

She looked at me without saying anything for a long moment, her face flushed red and mouth slightly agape. After an agonizing wait, she whispered, "It's a natural thing, but what if Ava had seen you like that? Did you even think about that?"

I stuttered back, "I thought I had the house to myself for another half hour. Of course I didn't forget about Ava, mom."

"And using her panties? She would feel so violated. All the porn in the world on your phone and you take your sister's underwear. They aren't even lingerie! Where are they?

I pulled the cotton briefs from my pocket and handed them to my mom. She walked up the stairs and I followed her as she went into Ava's room and to her dresser to put them away. As she folded them she suddenly brought them to her nose and looked at me. "Where did you get these?"

"The hamper," I replied meekly.

"I don't even know what to say to you, she huffed and walked to the dirty clothes to discard the panties. In one of the hampers next to it was a pair of her own panties, a lacy thong much more skimpy than the panties I had of Ava's. "At least use something sexy to get yourself off instead of your sister's underwear." She flicked them at me and I caught them and brought them to my face and smelled my mom's panties right in front of her.

"I'm so sorry. Please don't tell dad" was all I could mutter.

"Tell dad you like to sniff his wife's and daughter's used panties? Good call. He would completely explode." She looked down and saw my boner pushing prominently from my sweatpants and said, "take care of yourself before Ava gets home."

"With this?" I asked, holding out her thong.

She reached underneath her knee length skirt, pulled down a black lace g string with a partially transparent crotch and dropped it on the floor. "Use whatever you want, but this stays between us. You're welcome, by the way. Your sister would be disgusted and your dad would kill you."

"So you're not disgusted?" I slid my hand in my pants and sniffed her underwear. She gasped again, but didn't say anything.

I stroked myself under my pants and stared at her. Her blouse showed a little cleavage, and I was staring hard. I looked in her eyes and asked shamefully, "Can I see your boobs?"

She mumbled under her breath and unbuttoned her shirt, unclasped the bra from the front and pulled it aside, revealing her breasts. I started jerking faster, letting my pants slip down my thighs before coming before I could warn her, covering her skirt and torso, even getting some spunk on her exposed tits. She watched as I stroked the last bits of semen out on the floor, pulled her shirt and bra over her head to put in the hamper, then walked by me and said "Clean yourself up," before going to her room. She left the bedroom door open and went into her bathroom. I took a shower, then put clothes on and noticed her soiled shirt and bra on top of the hamper. I decided to ask her what she wanted to do with them and went into her room. I knocked on the bathroom door and opened it. She was in the shower as I asked her what to do, and opened the curtain to answer. Her full bush was on display now as well as her tits. "Throw it on the floor. I'll take care of it."

I just stared at her crotch. I could see her slit through her pubic hair, and she rubbed her soapy hand on it, saying "get a good look?"

I hobbled out of her room once again rocking a huge erection. She hadn't even gotten mad at me, and I got to see my mom fully naked just minutes after she saw my cock. I went back to my room and shut the door this time before jacking off again. I heard my sister come into the house. I crept out of my room and met her as she got to her room. I quietly followed her inside and told her the basics of what had happened; mom had caught me masturbating and that I accidentally saw her naked in the shower. Ava decided we should just go ask her what was for dinner and pretend there was no drama between the two of us. I reluctantly agreed, and we walked past her partially closed bedroom, Ava leading the way. The carpet made our footsteps almost inaudible, and my mom didn't...