Getting caught by my younger sister led to my first sexual experience. This is 100% true.
When I was growing up I used to regularly masturbate with my younger sister's dirty panties. It was the closest I could get to a girl's pussy at the time and I found her smell intoxicating, I would always have the most powerful orgasms when inhaling the musky sweet scent of my sister's pussy. Whenever I had the chance I would look in the laundry hamper and take every pair of my sister's panties out and smell them all. Then I would take the most stained pair and rub the area where her pussy had been all over my cock, after which I would wrap them around my hard cock so that her stains are in contact with my penis. Then I would take the strongest smelling panties and inhale them deeply whilst masturbating with the other pair, which would always end very soon after with a very powerful orgasm. I was always careful not to get any of my cum on her panties and I would put them back in the hamper in similar places to where I found them, in case my mom noticed anything when she did the laundry.
However, one afternoon I was at home feeling horny and I saw my sister, who had been sitting around all day in her pajamas watching TV, walk into the bathroom wearing her bath robe. I knew she wore panties under her pajamas because sometimes I could see the top of them showing. Being in a horny state of mind I immediately thought of her panties which she would have just taken off and would probably have been wearing since the morning before. I heard the shower turn on so thought I would be safe for at least ten minutes or so with my heart racing I quickly went into her bedroom and to my joy I saw her pajamas in a pile on the floor with her panties still inside them.
Knowing I had to be quick I picked out the sexy white patterned panties with pink trim and they felt warm which made my cock instantly rock hard. I took out my cock and knelt on the floor and noticed a small blue bra hanging over the end of my sister's bed. I grabbed this and hung it over my hard cock, intending to rub the small cups where her breasts had been over my penis. I turned my attention back to the warm panties and examined the inside, they had plenty of stains which were probably a result of being in constant contact with her pussy for such a long time. I touched this area with my fingers and it felt warm and moist, which made me think how warm and moist it must be inside her pussy, and my cock was now rock hard and throbbing. I could still hear the shower going so I raised the panties to my nose and took a big long sniff like I always did. Pow! It was her familiar smell that turned me on so much, but much, much stronger than it has ever been before. It was so intoxicating that at first I thought I was going to be sick, but then I felt a wave of sexual energy running down my body and as it reached my penis, I ejaculated uncontrollably with the strongest, longest orgasm of my life. I hadn't even touched my penis and my cum shot out high up to my face, covering the panties that were held to my nose and went all over the bra that was hung over my cock.
Breathing hard and with my heart pounding, I knelt on her floor for a moment, covered in my own cum, still feeling quite shocked at what had happened. But then my thoughts turned back to my sister in the bathroom and I noticed the shower was no longer running. In a panic I threw the bra and panties to roughly the same place as I had found them and stood up to run back to my room next door. As I got to her door however, the bathroom door opposite opened and my sister stepped out in her bath robe. I ran into my room with my still hard, dripping cock poking out of my shorts and cum all over my t-shirt. I shut my door but I knew she had seen me and that she would find my cum on her bra and panties.
I stayed in my bedroom for the rest of the day, not wanting to face her or my parents in case she had told them. When I finally did see her the next morning, she gave me a slightly strange look but spoke to me normally and didn't mention anything. Maybe she hadn't noticed anything at all I thought.
A few days later it was the morning and my parents had gone out to a garden center. My sister had her cute but annoying, obnoxious friend sleep over the night before and they were sitting on her bed playing a video game as I walked past. 'OH MY GOD YOU WANT TO FUCK YOUR SISTER' shouted her friend. My sister put her hand over her friend's mouth but it was too late. 'What?' I said, and her friend told me that the night before my sister had told her that she had seen me running out of her room with my cock sticking out and she found sticky stuff on her clothes. My sister looked extremely embarrassed and didn't say a word. I was mortified but decided I had to tell the truth so I explained that I didn't want to fuck my sister (ok so maybe that wasn't true) but that I like the smell of pussy and hers is the only one I could smell.
As she asked me questions she went from being her usual annoying, rude self, and started to become quite intrigued. I answered her questions and told her that the smell of pussy makes me incredibly horny and makes my cock harder and my orgasms much more powerful, and I also said to them that I just want to smell pussy, not specifically my sister's pussy, and that if I had access to someone else's panties then I would use those instead (although in retrospect this probably wouldn't have been true, I have sniffed the panties of quite a few women since and none of them have ever made me cum as hard my sister's used to).
At this point my sister's friend, now very intrigued, asked if I wanted to smell hers. Not knowing if this was an offer or merely a question, I just said yes. She said OK but she wanted to see me cum from her smell. Realizing she had probably never seen a boy cum before, I agreed but said that she had to help me by stroking it. Amazingly, and with a very cute and eager smile she said yes.
I stood up and pulled down my pants to show the girls my cock which was already growing hard, and seeing my sister and her friend staring at my rapidly growing cock made it go rock solid. Her friend made a cute giggle but my sister was still silent and looked stunned. I told my sister's friend to give me her panties and, still sat on my sister's bed, she reached up her night dress and pulled off her panties, and as she did so I got a brief but clear look at the virgin pussy I was about to smell. She already had a covering of soft, dark hair above her perfect slit and I was incredibly turned on by my first view of a girl's vagina in the flesh. She handed her blue spotted panties to me which were lovely and warm, straight from her beautiful pussy and I put the gusset to my nose and inhaled deeply. Her smell was quite different to my sister's, almost creamy and I was hard as a rock.
I always noticed the different smell I would get from my sister's panties depending on if I sniffed the part where her pussy had been touching. With my sister I liked the smell of her pussy much more and what I would like to do to it, whilst actually smelling it. However, I took a moment to have a look at the panties I was smelling and noticed a small white stain about an inch long that her pussy must have made. I moved my nose along to this area and took a long sniff and a lovely musky, strong, very sexual aroma filled my nostrils and I felt like my cock grow another inch. I told her how fantastic her smell was and how horny it made me and she giggled and smiled but still looked completely fascinated. She told me she wanted to see me cum so I told her to stroke and it would. Surprisingly quickly she moved forward on the bed and wrapped her hand around my cock from underneath and started awkwardly masturbating me, faster than I would have liked but I was too busy enjoying her aroma and my first ever hand job. I wanted it to go on forever but sadly the combination of her wonderful warm musky smell, the sight of a hot girl with my erect penis in her hand and the feeling of her soft hand stroking me made me ejaculate all over her hand and my sister's bed in a matter of seconds. The shocked look on the girl's faces was priceless. She remarked how hot my cum felt on her hand, and played with it with her fingers and told my sister it was hot and sticky. My sister, still silent, refused to touch my cum but when her friend tested what it smelled like she held her hand up to my sister's nose and my sister, quickly glancing up at me to see if I was watching, took a quick smell of the cum she had just watched spurt out of her older brother's hard penis. Suddenly feeling a bit awkward that I had shot my load all over my sister's bed right in front of her, I left for the bathroom where I immediately jerked off once again at the thought of what had just happened.
Nothing else ever happened with either my sister or her friend, but I continued to sniff and masturbate with her panties until I left home for college, and I would always try to get them as fresh off her pussy as possible. I will never forget her smell.