I have been friends with George since we were in middle school and he has a younger sister. As the years pass she developed into a very sexy woman. One time I was at my friends house we were just hanging out and he went to the store to buy some drinks, I stayed behind.
I was looking around his backyard when I noticed his sister's bedroom window. I looked inside and his sister was naked in her room. As I continued to watch she lay down on her bed and starts to touch herself, she rubs her pussy making herself wet then she puts two fingers in her pussy.
She penetrates herself so hard she squirted on her bed then she licks her fingers to taste her pussy. I got turned on by watching I began to masturbate outside her window. Now whenever I see her all I can think about is her masturbating in her bedroom.