OK, I was 13-years-old at this time, and I had been masterbating for maybe a year or so. My older sister (Ann) had a friend (Katie) over for the night. Ann and I shared a bathroom which was located between our two rooms, with doors into each of our bedrooms. It was in the summer so we didn't have school and both mom and dad went to work early like around 6:30 AM, so the three of us were home alone.
I think it was around 7:00am when I woke up and needed to pee. I didn't hear anyone else up yet so I went into the bathroom and peed. Ann's door was closed, but I left my door partially open after I finished, not really thinking. When I got back into bed, it was a warm morning so I didn't pull the covers up over me and I had left my jammy bottoms off after peeing, and this was my favorite time to masterbate.
I started by gently playing with nipples, rolling them between my fingers and pulling on them, getting aroused and feeling myself starting to get wet. Then I would start to play with my labia, and slide my finger in me while pressing the palm of my hand against my clitoris and rub it in a circular motion. I would fantasize about my finger being someone else, sometimes a boys penis or even another girls finger in me. By this time, I had closed my eyes and was beginning to moan, and just about to cum, when I heard someone in the bathroom, opening my eyes, I saw Katie in my open doorway watching me. My heart was beating so fast and I didn't quite know what to do, she had to know what I was doing, but I quickly tried to pull the covers up over my exposed body, (My t-shirt was pulled up above my small breasts plus I had no bottoms on either).
Katie disappeared from the door, but I could hear her in the bathroom. I kept waiting to hear Ann's bedroom door close, but I didn't hear anything. Finally I got up enough nerve to get up to close my door into the bathroom. When I got there, I peeked in to see if Katie was still in there, I didnt see her at first, so I stuck my head in further, and saw her standing in the shower, completely nude, playing with herself, without the water on. I stood there watching her for a minute, then realized what I was doing and went back into my bedroom without closing the door, Katie followed me into my room and asked if she could get into bed with me.
I was so scared, but didn't know what else to say, so I said if you want, sure. As she got into bed with me, she made sure I got a full view of her privates, she was partially shaved, and her labia was glistening with wetness and I could even notice her scent. She touched me immediately with her hand, and coaxed my legs apart, and began to rub me gently, as I lay there with my legs spread wide until I started to cum. It was the most intense orgasm I had ever experienced, I was arching my back, thrashing, opening and closing my legs, as Katie kept pressure on my clitoris and slipped her finger inside to feel my vagina contract, open and contract repeatedly. I also passed out. Katie jilled herself, then went back into my sister's room.
I never talked to Ann or Katie about this event, but it was my first f/f sex, and strongly preferred that. Connie