This happened when I was 13.
Ok, so it all started when my sexy cousion came over one weekend, think it was Christmas but doesn't matter. Anyway she came over, and before I never looked at her in a sexual way, but she had just turned 14 and started going through 'the changes.' She had regular sized boobs, 36C. and now that I realize, she also has a nice ass.
Anyway, so she came over and my parents wanted to take my aunt and uncle out and they said that they were gonna head down to vegas for the weekend and asked if we wanted to come. Of course I said no. I hate going with family, but on the opposite side my cousin loved family and vegas. She said no, which was a real surprise. My mom said that they will be back Monday night round 9ish (they left Friday around 7ish.) My mother told me that I was not to have a party or get into trouble, also that my cousin is in charge. I said yea yea w/e.
They left and I went up to my room and started playing xbox and I guess my cousin started watching t.v. Around nine she asked me if I was hungry and I said yea. We ordered pizza and ate, then around 10 she came into my room and said she was bored and if she could play with me. Since I'm usually nice to kids my age I said yea. We played for about 30 minutes until she 'realized' that she needed to take a shower, and I thought to myself holy crap I do to. She asked me if I had taken one today and I said no. She said didn't your mom say you need to take one everyday? I said yea so, she said come on. I'll let you take one with me.
I got hard as a rock just thinking about her naked. I got up as fast as I could. She started heading to the bathroom, when I said let's take it in the master bathroom, which was a whole lot bigger. We got there and I started up the water. She got undressed until she reached her bra and panties. She told me to get undressed but leave my boxers on. I said ok and did. Then I said well are we gonna take a shower with our stuff on? She said no, and removed her panties and bra. I got to see my first pussy ever and she looked tight as a fuck.
She said your turn, but I pretended that I couldn't hear her from the water. I guess she didn't care and came over and took my boxers off for me. She gasped as she saw that my 6 1/2 inch boner just popped out. She said woah, and I said sorry you make me horny. She climbed into the tub and I climbed into the other side. The water was high enough and could cover my boner. We started talking and then to my surprise she said spread your legs out, and I didn't ask I just did. She climbed on top of me letting my boner rub up against her pussy, and we made out for a little bit then she grabbed my dick and started to jerk me off.
In about 10 minutes I was ready to cum and she pumped faster and harder. I came a good load all over her hand and my lower belly. She said wow and grabbed some off my belly and licked it. I guess she liked it cause she licked me clean. After the water had gone down a little and when she laid back I could see her pussy. I told her to spread her legs now and she did. I bent over her and started to feel her pussy. I slowly stuck two fingers in her and gently pushed them in and out and started to rub her clit. She was moaning softly but after awhile she was moaning much louder. 'Harder jakey Harder', she said.
In another few minutes she squeezed my hand between her thighs and pushed my fingers into herself and came with a shudder, then kinda just lay there with her eyes closed moaning and saying 'fuck jakey your soo good at this'. After we took a shower, and I fingered her one more time before getting out and drying off. When we got out I went downstairs after changing and then I heard the doorbell ring and went to see who it was. It was my friend who lived next door asking if we were all right that she heard loud noises. Whoops. I said yea and closed the door, went up to my room and my cousin was in my bed and asked if she could sleep with me tonight. I said sure.
I put in a movie to help us sleep, got into bed and she got naked and cuddled up against me, kissed me on the cheek and then laid her head on my belly. We did this for the rest of the nights she was here even after my parents got back. She's 19 now and I'm 18 and we really don't do it any more but she brings it up a lot.