My Sister And I

When I was around twelve to thirteen I started getting really interested in what girls looked like naked, problem was no girlfriend and none of the other girls I were around would do anything anyways. One day in the summer, sister and I were at the beach with our sitter, she was there to make sure we did not burn the house down for the most part. All she really did was watch TV all day anyways, so we get back and head upstairs, both going to shower off and then have a snack. We flip for who gets to go first and I won, we were not even allowed in our mothers bedroom let alone use her bathroom at all.
So I get in there and am showering when I see someone, my sister is in the bathroom staring at me thru the sliding doors, I move the door back some and look out, she is naked and waiting there. I say in a whisper, why don't you lock the door and come in here with me? She did not even hesitate, walked over locked the door, came right back and stepped in with me. I let her have the water to wet herself down while I soaping up the wash cloth ready to scrub her down, we switched back and I told to put her arms up. She is two years younger than I am and her breasts had started popping out and looked like two big nipples and she had some light pubic hair, she giggled as I washed her body then just reached out and grabbed my cock asking why it was so big now.
I told her because of you, this is fun as I ran my soapy fingers thru her pussy lips and played with her nipples, she was enjoying it and squeezing my cock whenever she could then I had her stroke me off with both hands all soaped up. Our first playing around session went really great!
So I am in my room still just happy as fuck about showering with her and trying to come up with some way to get her naked again. She comes into my room wearing this long t-shirt she had, it was like a beach cover up really but she liked wearing it all the time. She had a plate with our snacks on it saying Julie made us this and sets it down on my bed then as if God was just completely giving me a great day she sit with her legs crossed and nothing on under the cover up. I am staring right at her pussy eating my snack across from her and she says thought you would like seeing me again, show me your thing again. I just pull the leg hole sideways and have my cock hanging out of it with my legs open also. She is eating and just staring down at it smiling then says I like how it looks, leans forward and touches the head and shaft some.
We spent the next several hours in my room just touching each other, absolutely amazing first day of exploring and we had the rest of the summer which was filled with sexual exploration.