Bathroom Incursion

My sister Kara just turned 18 years old. My name is Josh and I'm 10 months older than Kara. We have a very playful relationship. We aren't particularly close, but we do mess around with each other a lot and play the occasional prank and so on.

It was early December when our relationship became something a little more. We had both just finished high school and were currently on holidays as I was in the process of looking for a job while she was waiting to hear back from colleges. She had always been smarter than me.

These holidays I had gotten into the habit of getting up very late and showering around lunchtime. Kara was up early every day as she is a fitness buff and likes to go on early morning runs.

One day in early December I was in the bathroom getting ready to have my shower when Kara burst into the room. I think it was an honest mistake, the door lock was broken at the time and until the shower started you couldn't tell if anybody was in there. We weren't used to knocking since the lock on the door only broke a few days before.

Kara burst in still wearing her jogging outfit. Tight red shorts and a tight red top that showed a surprising amount of her stomach. She is 5"10' tall with a slim athletic figure, shoulder length straight brown hair and green eyes. I had never really thought about how sexy she was before, but she definitely had that sex factor.

Myself on the other hand, wasn't wearing anything. I had just gotten undressed for my shower when Kara came in.

We both froze as we realised her mistake. Her eyes darted to my exposed penis and stuck there. I didn't move for what felt like forever. I could feel her eyes burning a hole into my dick and suddenly it began turning me on. I could feel it getting harder and rising into a full erection right in full view of my sister.

It was probably only seconds later, although it felt like 5 minutes, I snapped out of my stupor and covered myself with my hands.

"Get out!" I cried, not thinking of anything better to say.

"Sorry." she said, but she had a large grin on her face.

Then she left the room and closed the door. She was going to tease me so bad for this, especially for getting an erection in front of her.

When I emerged from my shower Kara never said anything, didn't tease me at all. From then on I found myself thinking about her in ways I never had before. I realised how sexy she was and tried to imagine what her chest would look like topless. It was only fair I should get to see some day, since she had seen me. What a turn on.

The next day I was about to have a shower when for the second time Kara came into the room. I was only topless this time. She said sorry again and quietly left the room, but I noticed her eyes darting across my chest. I wasn't the most built guy, but I had some muscle. Was she trying to walk in on me again deliberately?

For the remainder of that day I couldn't stop myself sneaking peeks at my sister whenever I had the chance. At dinner that night she dropped her fork in the kitchen and barely bent her knees when she bent over to pick it up. This gave me a great view of her tight ass. My dick immediately grew into a raging hard-on. Luckily I was sitting at the table so nobody could see it, and my parents were facing away from Kara so they couldn't tell I was staring at her ass.

The third day I decided to see if Kara would enter the bathroom again while I was in there. The thought of her seeing me nude again was intoxicating. I almost undressed and waited for her like that, but I chickened out and remained clothed, sitting on the edge of the bath. My dick tented the front of my pyjama pants, already hard from the thought of my sister.

Sure enough Kara entered the room. As soon as she saw me there fully clothed she apologised and went to leave. I stopped her.

"Wait," I said, "Are you actually trying to walk in on me naked?"

My sisters face immediately went beat red.

"No, of course not! What would make you think that? I'd never."

She was very defensive and her mannerisms gave away her obvious guilt. I suddenly felt powerful and confidence rose inside me. On pure instinct I found myself pulling my pants down to my knees. My hard cock popped out into the fresh air and Kara's eyes snapped to it like they were magnetic.

We stood there for a while, nobody saying anything.

"Whoa!" exclaimed Kara, "it's huge."

"8 inches." I said, "Have a good look, you've clearly been dying for it."

Her eyes flicked to my face for a moment at that.

"Not true... I just thought, maybe I could catch another glimpse. I didn't think I was so obvious."

"Well your lack of teasing my erection the other day was the first give-away." I said.

"Oops," she replied, and blushed again. "Do you think I could touch it?"

My heart skipped a beat at the thought, my cock jumped in response.

"I suppose." I said, my voice caught in my throat.

My sister moved closer to me, today she was wearing jeans and a simple T-shirt. She slowly reached for my shaft and wrapped her fingers around it. I moaned softly in response. It felt so good. She started pulling on my cock, slowly jerking it as she bit her lower lip and looked straight into my eyes. Then suddenly she stopped.

"I should let you shower. Sorry again." she said, then she left the room.

I quickly jerked myself off to ease the tension, then had my shower.

After that incident, Kara started teasing me about my dick. She'd giggle at me all the time, and when nobody was around she'd taunt me with things like "Josh gets a hard on for his sister." I didn't mind it in the slightest, in fact every time she said it I did get a hard-on and she would quickly grope it through my pants when I did.

The day after Kara's short lived hand job I decided to get up early. I wasn't sure if she would walk in on me again, so I thought I'd turn the tables on her. I waited for her to get back from her run and go into the bathroom. I waited a few minutes and then entered.

My sister was standing by the shower completely nude, her ass in full view. It was wonderfully firm and round. My cock was already partially hard, but as soon as I saw that it almost ripped a hole in my pants.

Kara turned around in shock and covered her crotch with her hands. But there was nothing she could do about her tits. My eyes locked on to her petite pink nipples, they seamed to float in the centre of her perfect mounds. Her breasts were probably a B cup and looked like a nice generous handful. They were perfect. I think my mouth dropped open slightly as I stared at my sisters tits.

"Josh! What the hell?" she said.

I replied, "I thought it'd only be fair if I got to see you."

She just stood there shocked for a moment, then her mouth slowly cracked into a small grin.

"I guess you're right." Her hands dropped to her side, revealing her crotch to me. My eyes moved down from her perfect tits, across her perfect flat stomach and landed on her pubic mound. She was quite hairy down there, but I could see that it was neatly trimmed and wasn't growing wildly.

Kara then pointed at my crotch and said "Your turn."

I quickly removed all of my clothes, revealing my hard dick to my sisters gaze, oh what a turn on.

While Kara stared at my cock, I slowly moved towards her and reached for her jugs. I grabbed a handful in each hand and slowly massaged them. My cock jerked from the mental stimulation. Then Kara surprised me. My sexy sister reached down for my ass. She grabbed a cheek in each hand and pulled my pelvis towards her. My dick hit her stomach and slid up past her belly button as my body pulled towards hers. I released her tits and grabbed her ass as well. Her breasts squashed against me and my cock was now mashed between our bodies and I couldn't help myself. I thrust forward and slowly pumped my cock against my sisters navel.

"Oh yeah." she moaned.

I began to pump against her stomach a little faster, but soon she pulled away.

"I know it's wrong, but I can't help myself, it just looks so inviting." she said.

Then she slowly lowered herself onto her knees leaving my cock only centimetres away from my sisters face. She then grabbed my shaft at the base, angled it up again and slowly licked my cock all the way from the base to the tip. Then she looked into my eyes and smiled.

"Holy shit!" I said, "I don't know if you should be doing that, but it feels so good."

Then my cock popped into my sisters mouth and her thick lips slowly travelled down my rod until she was about to choke on my dick.

You see, Kara has perfect massive sensual lips. All through high school she was teased for having blow job lips, and now I was actually experiencing them being used for that purpose.

My sister started to bob her head on my cock, stroking the underside of my shaft with her tongue. My hands moved to her head and lightly held onto some of her hair, then pulled on it slightly as she moved back and forth over my rock hard cock. I could tell she had done this before, she worked her tongue in a way that almost made me explode with each stroke.

Eventually I couldn't take it any more and without giving her any warning I became to cum, HARD. I shot blast after blast of hot cum into my younger sisters mouth. She pulled herself off my dick slightly at the same time to try and get some air. Semen poured over her lips like a waterfall and travelled down her chin and neck to rest on her perfect tits, obstructed by her nipples, a few streams slowly flowing past them towards her naval. When I finally stopped cumming I removed the head of my cock from her mouth.

"Sorry." I said.

She couldn't respond, despite the torrent that had run down to her breasts, her mouth was still half full of my white seed. She showed it to me, then swallowed the whole lot in one go.

"Don't worry, I was the one that went down on you. I wouldn't have done it if I didn't expect a wad of cum to end up in my mouth."

Wow, my sister was turning out to be rather slutty. She engulfed my cock between her lips again and proceeded to lick me clean.

"Perhaps we should keep that to ourselves, eh?" she said when she was done and stood back up.

"Sounds like a good idea." I said. I then redressed and left the bathroom as Kara started running the shower, my cum still plastered all over her face, neck and chest.

I went back to bed and rested, I couldn't actually fall back to sleep. Later that morning I had my shower at the usual time. I stripped off and waited to see if Kara would enter, I wanted another blow job. But she didn't. I worried that perhaps she regretted what we had done. When I left the bathroom I quickly found that wasn't the case.

My sister playfully teased me all that day, grabbing at my cock whenever nobody was around and once even whispering in my ear while our mother was standing two feet away.

"You wanna blow another load of cum down my throat don't you?" she whispered.

I just nodded to her in response, I was stunned by the brassiness of her actions.

That night I caught up with a friend and we just messed around the way we usually did. It took my mind off my sisters hot tits and lips for a while.

The next morning I intended to get up for Kara's shower again but slept through my alarm. So I went to have my shower at the normal time and stripped down to nothing while waiting to see if she'd show. This time she did. My sister entered the bathroom, already removing her top as she walked in.

"Looking hot." I said, but she didn't respond.

My sister ignored me as she stripped off all her clothes right in front of me. I stared at her smoking hot body as she walked over to the bench, her hips swaying with each step. Without even realising it, my hand had moved to my cock and was stroking it absent mindedly. It was already hard.

Kara bent herself over the bench, revealing her ass and pussy to me at the same time. Resting on her elbows she looked at me in the mirror but didn't say a word.

"Oh I see, you want me to go down on you?" I asked.

Again she didn't respond, what was she playing at?

I don't know what made me make my next move but I slowly approached her and then holding my hard member in my hands I gently pressed the head up against her hairy cunt, never removing my eyes from hers in the mirror. She just looked right back and continued to remain silent.

No way, was she giving me permission to slip her my cock? Should I go through with it? My parents were home a few rooms away, even if I did go through with it, right now was a bit risky. My hips answered for me as they pushed forward almost unconsciously. My rock hard cock slipped past my sisters pussy lips with a slight sucking sound and before I knew it I was balls deep in my younger sister. I placed my hands on her ass and softly gripped her cheeks as I prepared to fuck her.

Kara closed her eyes and rolled her head back as my shaft hit home, almost penetrating her womb itself. She groaned slightly and I began to withdraw fully from her. As soon as my knob emerged from her lips I pushed it back in and penetrated her fully once again, almost splitting her in half. Then I began to pump in and out of her. Slowly at first but eventually becoming a jack hammer, nailing my sister from behind with everything that I had. The sound of her ass slapping against my stomach with each thrust was deafening. I held onto her ass as tightly as I could as her tits rubbed against the facet and her head bounced backwards and forwards. She made an Ah-AH-ah-Ah sound in time with my thrusts.

The thought that our parents were only a door and some hallway away while my cock pistoned in and out of their daughter was an incredible turn on. I'd probably die if they caught us, but the risk made it so hot. It's amazing they didn't hear us.

We fucked like this for perhaps 5 minutes at the most, the incredible heat from the situation was unbearable and I couldn't hold on any more. Right as I was about to explode in my sister's twat I realised I had no idea if she was using any birth control. I released her ass and pulled my cock out of her right as I began to erupt molten semen. The first blast splattered squarely against my sisters pussy and ass hole as I struggled to aim over her back. The proceeding blasts coated her left ass cheek and then most of her back with my cum. Even the fourth and fifth blasts still had a bit of power and distance to them from the power of my orgasm.

Finally, as I'm wiping my dick clean against her right ass cheek Kara speaks for the first time since entering the room.

"Oh yeah... That's exactly what I needed. Don't worry though, I'm on the pill."

"If I knew that I'd have cum inside you." I replied.

"That would've been nice. Perhaps next time." she said.

"Should we really have done that?" I asked.

"It's fine, I don't regret it. I didn't know what you'd do. I just planned to lean over the bench and let you do whatever you wanted. You chose wisely I must say."

After that we both got into the shower together. Kara washed the cum off her pussy and back and then we showered together, exploring each others bodies as each of us washed the other. I rubbed her clit the whole time she was washing my body and she jerked my dick as much as she could while I was washing her. By the time we got out of the shower I was well and truly hard again.

Kara knelt before me as soon as we emerged from the shower and began to suck my cock once more. This time she seemed to suppress her gagging more so than the first time and she let me drive my cock deeper into her face. I built up a savage rhythm, slamming my balls into her chin as I skull fucked my sister. I couldn't hold on as long as the first time and quickly started to cum as she was deepthroating me. She started to gag and pulled her face off my dick as I unleashed another torrent of spunk. I coated her face with a thick layer of semen.

"Hell yeah!" she said once I was finished glazing her face and she'd swallowed what cum I'd deposited into her mouth. She was really liking this, which surprised me.

My sister licked and sucked my dick clean and then started getting dressed, her face still covered in cum. She could only see out of her right eye, as her left was sealed shut by a thick wad of semen. I also got dressed, then once Kara was all dressed she left the bathroom. I ran after her in shock and watched her walk into her bedroom, face covered in cum and fully exposed to the risk of being seen by our parents if they wandered past the hallway. My heart lurched in my chest, but slowly calmed down once her door was shut. I can only imagine what she did with that coating of white glaze I left on her face, but I like to think she swallowed every last drop.

The extreme risk Kara had taken turned me on, my cock was already becoming hard again as I ducked into my own bedroom. She was becoming a bit of a slut, or perhaps this was her true nature that she was suppressing all this time. Whatever the reality was, showering was going to be very interesting. At least until she leaves for college.