My moms new daughter

I was a boy of about 12 fixing to be 13 when my sister found out my very personal secert.Its was in the beginning of the summer and we were out of school and at home all the time.One day i was walking around the house and noticed that my sister was gone with her bedroom do wide open.
So,I adventured of into her room looking for something that was going to turn me on.My sister was a year older than me and i was always watching her.she was the sister that every guy wanted to have .She was a very sexy girl for her age.Being 16 was showing on her and i always wonder what it would be like to be like her.So,Anyway back to my sisters room that day i walked into her rooma nd started going threw her things when i come to what i was looking for.I found her underclothes and started looking at them and there was a pair of black thong panties that i loved and i put them in my pocket and went back to looking for something else so i was looking when she walked in and asked me what i was doing.Nothing just looking for some papaer and she told me to leave and i did.
I went to my room and took off my pants and put her thong on and put my pants back on.and them my mom started calling me saying my friends were here to play so i went out and played with them all day and about 6 my mom came out and called me back in to get ready for bed.So, I went upstairs to take a bath when my sister came up to me and told me i know what you got out of my room and i won't tell no one if you promise to wear them for me and i told her i already have them on.She told me to show her so i took her into my room and showed her.I pulled my pants down and took them off and she said wow your but looks better than mine.and she rubbed on it for a little while then told me to keep our secert i would have to do something for her and i said whatever it takes to keep the secert.She told me to wait till firday and she would let me know.So, I went and took my bath and went to sleep with her thong on.it felt so good wearing them.But, I woke up looking at my mom standing in the door looking at me.She asked me what i had on and ask me how long i had been wearing those thongs to bed and i told her it was the first time and i would'nt do it no more.But,She stopped me and said that she thinks i look cute in them.And she asked me if i was trying to be like my sister and i told her that i have always had a fantasy about being just like her.And my mom said that she would make that fantasy come true.