Other girls have written here about their experiences with their brothers. I too have had similar experiences. Mine though have turned into an addiction.
My younger brother is like most guys of his age (16) horny ALL the time, and he can be a jerk. He often tries to see up my skirt and sometimes, especially just lately, has been asking me questions about whether I masturbate, have I gone the whole way yet, stuff like that. I guess he is just curious and as he is really shy with people outside the family, I can guess he hasn't had the chance to find out for himself. Usually, I just laugh his questions off and divert his attention to something else. Lately though, I have been becoming aroused partly by the brother/sister stories on here and partly because he was clearly getting a hard on sometimes.
So two days ago, our parents were out and he came into my room and sat on my bed. He started asking about how it feels for a girl when she is horny. I was going to change the subject but then I thought what the hell. I told him that I get tingly between my legs, my breasts get harder and sensitive and I get wet. He asked if I masturbate and I said sure, don't you? He told me that he did but that he was scared as a lot of stuff came out and he thought a girl would freak if she saw it. I told him that quite the contrary, a girl would be flattered if she made him cum a lot. I could see he had a nice hard on by this time too. He asked me how girls do it and I told him I like to do it lots of different ways depending on how I am feeling. Sometimes, I like to masturbate gently and in bed, other times I like to do it in more daring places or cum in my panties.
I was sitting on my bed at this point and I just said have you ever seen a girl's pussy? He said he hadn't and with a dry mouth and rapidly beating heart, I pulled my panties to one side and showed him my pussy. Then as he watched I started to rub my clit. I felt so horny and so bad doing it in front of my brother. Then I stopped and reached out to him. I felt his boner through his shorts and then tugged them down. My little brother is a VERY long way from being little! I wrapped my fingers around him and started to jack him off. At the same time I took his hand and showed him how to finger me. When I saw precum on the end of his cock I slipped my top and bra off.
I said I want you to cum whenever you are ready, just tell me when. By now he was kneeling up and leaning back a little and had stopped fingering me. Then he said I'm gonna cum. I cupped his balls in my other hand and jacked him full length. I felt him tense then he shot his load. I made damn sure it went on my face and my breasts. And BOY can he cum! He just spurted and spurted. At least seven good sized jets. It ran down my tummy and between my legs. When he came down from his cum I got him to finger me to a fantastic orgasm. I told him how he was making me feel and when I was about there. While he was doing this, he got hard again. I loved the badness of all this.
I lay in bed that night, and masturbated myself so much that my clit was raw the next morning. He told me he jacked off into a pair of my panties I had told him to take from the laundry.
I find myself aching to do more with him. I know it's wrong, I also somehow seem to know this is just a phase for us both. Something we need to do and get out of our systems.