Masturbating Together

I can remember the first time like it was yesterday. I was 17 and my sister, Clara is 10 months younger. It was a lazy Saturday late afternoon. Our parents had gone out for the evening to a party, suggesting they might stay if they were having fun. My sister was getting ready for a date, spending wayyyy to long in the bathroom. I was extremely horny, as I almost always was, and couldn't wait for everyone to leave so I could get down to masturbating. Now, my sister and I weren't particularly special in the looks department as teens. We both had started puberty when we hit our pre-teens and now had acne that was more than most of our freinds. I was taller and quite thin and didn't get any interest from girls. My sister was short and pudgy, but had a decent figure with round butt and rather large tits compared to other girls our age. Again, the acne made success with the opposite sex rather dismal. However she managed to get a date with a guy a little older than both of us and she was excited to to go out.  Our parents had left and my sisters date pulled into the driveway. She bounded outside and jumped into the car. I was alone at last! I immediately headed for my room which had a jack and jill bathroom between my sisters room and mine that we shared. No worries, our rule was that if the other's door was closed DON'T COME IN! I closed my door, (but hers was still open) stripped down to nothing and layed down on my bed, grabbing my semi erect cock in my right hand and sqeezing a dollup of KY onto it with my other. Although I knew I wasn't anything special in the looks department, I had seen enough porn in magazines to realize that my cock would rate in the upper percentile. I regularly measured it and by time I was 16 it was just about 9 inches from the inside base to the tip. My balls were also rather large and when I came I always had cum all over my chest and sometimes on my face and hair. Just as I began to get into some nice slow stroking I heard our front door slam and some very hurried stomping up the stairs toward my room. I kinda paniced thinking someone would burst in but then realized it was my sister, thinking she must have forgot something. I soon realized she was whimpering on her bed, then crying, then BAWLING her eyes out. I tried to ignore it and kept stroking but it was a distraction. Then she called out, "JIMMYYYYY!".... can you come here? "What for!?"  I replied. "He dumped me!", was all she could say before starting to bawl again. Awe geez, if I didn't go she would soon just come over anyway.  This wasn't gonna be easy, shit, my hands and groin were covered with KY and her door to the bathroom was open. In order to clean up I would have to stand at the sink right in front of her open door which was right at the end of her bed that she was obviously laying on crying. I wiped my hands as best I could and just pulled my boxers over my slimy cock and balls, put on a T-shirt and headed to her room. I walked in to see her laying on her bed, dressed rather scantily in a very short skirt and a low cut blouse showing some decent cleavage. I moved over and sat on the edge of her bed and asked whats wrong. She said as soon as she got into the car they started talking and he just blurted out that "this wasn't what I wanted" and I better take you back home". I remember she looked at me with the sadest eyes and asked, "am I THAT unattractive"? Naturally that prompted any young males reaction to glance over the body of the subject to guage an answer. I glimpsed at her cleavage, her shape, and how she was laying with her legs slightly apart. Her look caused a flush of blood to my face and my heart to quicken. My cock stirred too. I replied to her question with the typical brotherly answer "you're great Clara". She just rolled her eyes, (I don't think any answer would have sufficed) and said something that would change our relationship and lives forever.... "Oh well just go back to your room and finsh what you were doing". "What do you mean by that?" I responded. Then she reached out, her finger pointed out, and poked the head of my cock as she said, " I know what you were doing when I got home". The feeling of my cock being touched, even as slightly as it was, in the state I was already in, caused another surge of blood to my face, heart rate quickening again and this time I could feel the pulse of fluid pushing up my semi erect cock which was being confined in a small space between the folds of my boxers. The head was tight against the fabric of my boxers and the seminal pre-cum fluid just pushed through the cloth, surfacing as large drip of clear pre-cum that then slowly stretched down to my thigh in a sticky string. "OH MY GAWD JIMMY DID YOU JUST CUM?!" My sister blurted out. "NO!" I said, "Its just pre-cum and if you know what I was doing then you should know why!" "Well", she said, "you can go ahead and keep doing it cause thats all I'm gonna do now since no boys want to touch me" matter-of-factly. I was puzzled since she didn't clarify "where" I should keep doing it. But I got up to leave anyway. As I headed back to my room she says, "you wanna do it with me?". I turned around to see her non-shallontly removing her clothes. She was down to her bra and panties. I could see a serious camel-toe and what were now obviously some really perfect tits. They were FANTASTIC tits! My cock went full hard. I went back to my room. My gawd what was happening!? I was soooo horny now, I thought what the hell, she asked for it. I went back into her room where Clara was now completly naked, eyes closed, vigorously flicking her clit. I dropped my boxers, sat facing her on the end of her bed and started stroking my already lubricated cock. She opened her eyes and looked straight at me, eye to eye. We stared at each others eyes as we masturbated ourselves. My heart was going a thousand miles per hour. I think her's was too. She broke our gaze and the silence by saying, "your cock looks too big for you". We both started laughing. It felt good but was sooo intense. I didn't know if i would cum until she started fingering faster and blurted out "when I cum its really messy", as she flicked her clitty really fast her legs began to shake and she arched her back, I started stroking faster just in keeping with her rythem, we both started breathing heavier and i could feel myself building up an orgasm. Clara looked at my cock as i pumped it hard. "I'm gonna cum Jimmy" is all she said as she bucked her hips off her bed and cream began spewing forth from her pussy. Wow! I'd never imagined a girl actually "cumming" with white fluid like guys have, but it was very white, very thick and there was lots. Seeing, well actually hearing her cum put me over. I started shooting onto my abdomen spurt after spurt. I was coated right up to my neck. We both panted out breath after breath as we re-composed ourselves from our climaxes.  And thats how it started, more to cum...