I was 13 at the time, I'd discovered an interest in girls and in masturbation, although neither I nor any of my friends would actually admit to ever doing 'it'. I was also totally inexperienced when it came to girls and would become hopelessly shy in the presence of any female I fancied and would like to ask out.
One of my friends was a boy called Andy who was a year older than me and had a sister Susan who was a year younger. Susan was cute rather than attractive with a mass of curly dark hair and a neat little body that was just on the point of starting to develop into something more interesting. She was bubbly and friendly, always with a smile on her face and, as I was about to find out, totally uninhibited and rather sexually advanced for her years.
The first time I met her she wandered into Andy's bedroom when Andy and I were working on a school project together. After Andy introduced us she chatted away wanting to know more about me and it was difficult not to like her she was so open and friendly. Eventually Andy went downstairs for a drink and Sue said 'Shall I undress for you....yes, I think I will.' With that she started to get undressed, right there in Andy's bedroom. Although it sounds ridiculous now I was horrified and embarrassed by what she was starting to do even though I had the chance to see my first ever naked girl. Shoes, socks and her dress came off until she was standing in just a white vest and navy blue knickers. I was saying that Andy would be back any second and she shouldn't be doing it, anything to try and make her stop. She lifted the vest up then seemed to think better of it, let it drop down, then gathered her clothes up and went to her room. I'm pretty certain that had I given her a bit of encouragement rather than being so embarrassed by what she was doing, she'd have taken the vest and knickers off too and would have stood there naked for me.
A couple of weeks later Andy and I were again in his bedroom when he went out for something. When he returned he said that Sue was having a bath and she asked if I wanted to go and watch her. I laughed it off and said no, again my shyness and embarrassment preventing me from seeing my first naked girl.
On another occasion with Andy there, Sue asked if she could see my cock, she wanted to see if it was like Andy's. Again I laughed and said no way, totally embarrassed. When she went out Andy said that nothing really embarrassed Sue and the two of them were quite open about things with each other. He said sometimes they would get naked together and Sue liked to play with his cock and show him her 'cunt' as she liked to call it.
Sue was always friendly, flirty and suggestive but she never offered again to undress for me, and she never got to see my cock, until that is one day during the summer. The weather was really hot, too hot to be in the sun, so Andy and I were in his room both in shorts and T shirt. Sue came in and she was wearing a little pink bikini and nothing else. Somehow seeing her in a bikini didn't get me all embarrassed in the way seeing her in underwear had and I let my eyes take in her bare legs and stomach and neat little bottom encased in her tight bikini pants. I think Sue must have noticed me looking at her because the next second she said 'It's far too hot in here, let's all get naked'. Before I could say anything she reached behind her and unfastened her top and took it off, leaving her in just her pants. She was still flat chested, her breasts hadn't really started to develop, but her nipples were quite puffy and prominent.
I was waiting for Andy to say something to stop things but instead he just said 'Yeah, why not' and pulled off his T shirt. I watched in horror as Sue pushed her bikini bottoms down and off and Andy pulled off his shorts and underpants leaving both of them naked. Seeing my first naked girl, even of Sue's age, should have been a time for celebration but instead I was overcome with all my old shyness and embarrassment again. Sue's bare bottom was really soft looking and cute, and round the front at the top of her legs she was still basically bare with just a few little dark pubic hairs starting to show leaving her little slit still quite visible. It was the first pussy I'd ever seen.
By now both of them were looking at me telling me to get naked too. I was beginning to panic as no way did I want to take my clothes off but Andy and Sue were getting more insistent and teasing me about it. Eventually I said I'd strip down to my underpants but keep them on. No sooner had I done that though than Andy grabbed hold of me telling Sue to 'get his undies off'. We ended up on the floor and although I struggled he managed to hold my arms and I felt Sue's fingers in the waistband of my pants and the next second she'd pulled them down and off over my ankles leaving me naked too. Naturally her eyes went straight to my cock which despite all the nudity was still soft. 'I've seen your cock!' she said 'But I want to see if it gets bigger than Andy's'.
Sue's hands then went to my cock and she started rubbing and fondling it, and with Andy still holding on to me there was no way I could stop her. At that time it didn't take much to get me aroused and less than a minute later I was fully erect much to Sue's delight and my discomfort, nobody had ever seen my cock erect before. Looking me in the eyes and grinning her next comment was 'Now I'm going to make you shoot'. As her right hand gripped my erection I suddenly realised what she meant and said 'No' but there was no stopping her. She pulled my foreskin back exposing the head and then began to move her hand up and down the shaft quite slowly and with just the right pressure. Wow, did that feel good! I'd masturbated myself many times but having it done by someone else for the first time and not being my own hand doing it felt wonderful. In an instant all my embarrassment and panic disappeared, there was no way I would have wanted her to stop now.
I then realised that Andy had let me go and was now alongside me stroking his own cock which too was erect. We'd seen each other naked in the school showers many times but again I'd never seen him hard before and I judged his cock was about the same size as mine thankfully. Sue started to speed up her movements and I could feel myself getting ready to cum. Seconds later my cock erupted shooting out cum all over my stomach and down Sue's hand as she gave a little squeal of delight. Just as I was finishing Andy then started spurting, again most of it landing on my stomach making a large sticky wet pool. It was the most intense and satisfying ejaculation I'd ever had.
Andy went and got some tissues to clean up when all of a sudden we heard a car outside, their mum had returned earlier than expected. Sue grabbed her bikini and ran to her room while Andy and I pulled our clothes back on, everything looking normal by the time she got upstairs.
Looking back it was obvious that it wasn't the first time that Sue had jerked someone off, she obviously knew what she was doing, and Andy later told me that she liked to do it to him when they were naked together. He also said that Sue liked him to play with her pussy too.
Over the next few months we had several other 'let's get naked' sessions together. After that first time all my inhibitions had gone and I was as enthusiastic about them as Andy and Sue. Andy and I would always get erections and masturbate in some way. On our second occasion I got to touch and play with Sue, and she loved seeing both of us with hard cocks as we came up with different ways of bringing ourselves off. That's for another post however if people are interested.