Chapter 1700 My Crazy Hot Sister(Incest/Taboo)

I don't know what possessed me that night, but I found myself standing outside my sister's bedroom door at three in the morning. I hadn't been able to sleep all night, even though I had masturbated twice already. I couldn't stop thinking about her. I guess it was because of earlier that day, at the pool at our aunt and uncle's house. I had never seen her in a bikini before, and she was wearing this tight little black string number, with small triangles covering her nipples and surprisingly very little covering her pussy. There was so little to it that it was ridiculous. Even though we were both eighteen, she would never have gotten away with it at home, but mom and dad weren't here, and our aunt and uncle let us do whatever we want. I think one time my uncle tried to have a manly talk with me about sex, and something along the lines of how masturbation was normal. I didn't understand a lot of it, but regardless my aunt and uncle are very allowing.