Growing up I lived next door to a girl who was one year older than me, and twins (boy and girl) who were two years the younger. I had a crush on the older girl, Kate, and we made out a few times but nothing more. The real fun was to be had with her younger sister, Amy.
One day we were hanging out in their basement, myself and the twins, Paul and Amy. I was 16 to their 14. Amy was a freshman and had started developing what would become a D cup sized set of tits. They were already a solid set of B's, and I had started becoming attracted to her as she started getting older. We had played grab ass a couple times but nothing more until this day. We were playing video games when Paul had gone to the bathroom. He had shouted out to us to come here and look what he found. I wasn't sure I wanted to go at first! But me and Amy went to see what he was so excited about. Seems he found a stash of his dads porno mags hidden in the ceiling. And these weren't playboys, they were hardcore, stuff I had seen but it was obvious Amy had not. We were scanning the pages and looking at a three way. Amy was having a nervous giggle and letting out some oohs and wows. We got to the climax of the pictorial, and Amy had asked what the white stuff was coming out the mans' thingy, as she called it.
Hmm, a chance at teaching some sex ed, I thought. Paul would chime in once or twice, he knew much more than his sister, but he left the explaining to me. So I started explaining about cum and how it makes women pregnant, and she asked if I was old enough to do that. I said I was and I'm pretty sure Paul can to. She asked all sorts of questions about cum, and one was do boys have to be having sex for us to cum. I said no that I can make myself cum, its called jerking off. She was intrigued by that, and it was obvious she did not know about masturbation, male or female. We discussed orgasms and what they were all about and told her an orgasm would make her feel really good and she could do it herself. She went from a giggly teen to an interested horny girl. She finally came out and asked if I could do it for her, she wanted to see my cum. Paul acted disgusted but I could tell he was curious to where this might go. I said I could but I would probably need some help to get excited, (not that the mags didn't already have me worked up)
She asked what kind of help I would need, and I told her that seeing a naked girl would get me hard, and since she wanted to see me naked, it was only fair if she got naked too and it would help make me cum. She giggled nervously but said she would take off her shirt and shorts and stay in her underwear. I replied that it wasn't enough to get me excited and she would have to get naked to see me cum. She agreed and started taking off her shirt then her shorts as I was kicking off my shorts. She was wearing a pair of white cotton panties that hug her tight little body and I could feel my dick straining against my underwear. She couldn't stop staring at my crotch when I slid my underwear down my dick sprung out and she gasped. I'm only six inches but fairly thick, and I said she had to finish getting naked with me. Paul was sitting in another chair looking at his sister and feeling around his cock.
Amy proceeded to finish taking of her bra and panties and I saw those lovely tits for the first time, as well as her sparsely covered pussy. She was trying to cover up but got more comfortable and stopped trying. I was harder than ever, and she said ok I'm naked now how can I make it cum? I told her I would show her and started stroking my throbbing cock.
She looked on in amazement as she slowly opened and closed her legs, instinctively it seemed. The only time she took her eyes off my cock was when she glanced over at her brother who now had his maturing dick in his hand jerking it off. She asked how it felt and I told her it felt incredible, and she could feel good too if she tried touching herself. She was facing me on the couch as she slowly opened her legs, I could now see the pink of her pussy lips and was fixated. I told her first to try rubbing her tits and her nipples to see if it felt good. She massaged her tits and grazed her nipples and giggled saying it made her tingle. I said that's good and it will feel even better. I then told her to use one hand on her nipples and use the other hand to feel her pussy. I was stroking hard and trying not to come, as was Paul, who said nothing but watched.
She gingerly started feeling around her slit, and I told her to take one finger and feel around for a little bump at the top. Well she found it pretty fast as she rubbed her clit for the very first time, and let out a very loud ohhhhhhh. I told her that was her clit and if she kept rubbing it she would orgasm and feel incredible. After watching a virgin break her masturbating cherry, I couldn't hold on any longer. I told her I was going to orgasm and shoot my cum and she watched my dick intently. As I grunted I shot stream after stream of cum into her direction, with most of it landing on the couch between us, with a little bit hitting her foot. She yelped in excitement as I came, with Paul following me just seconds later. She stopped her masturbation to examine my cum by touching what was on her foot. She replied that it was warm and sticky as she rubbed it between her fingers. I told her she could finish her orgasm but replied that she already did. I know she didn't, as I think she got a little nervous when the moment broke and said her parents would be home soon. She went to the bathroom and got dressed and I cleaned up my mess while Paul was getting his stuff cleaned up.
We went on to talking more about it, and I told her to try it when she was alone and it would feel even better. About a week later she happily told me that she made herself officially cum and that she wanted to see me shoot my cum again. We shared many more mutual masturbations, but never had any physical contact. Her brother only joined in one other time, I think he was uncomfortable around his sister. But it sure was a good time teaching my neighbor Amy the joys of masturbation.