My brother and I are 5 years apart, with me being the big sister. I am 23 years old, 5'2", weighing 120 lbs, 34C tits, 34 hips and 24 inch waist. I am a brunette that is waist length. I wear glasses. My brother is 18 years old, 5'7", and weighing 140 lbs. So he is rather skinny in High School plus he played football.
I was asleep one night and a noise woke me up and I looked around to see what the noise was. I could barely make out the other side of the bedroom in the dark where my brother was sleeping on the other twin bed or I thought he was sleeping. I noticed a movement and thought to myself, 'OH WOW! He is jacking off!'
So I cleared my throat loud enough for him to hear, "Ahemmm Ahemmm,"
It scared him so much that he covered himself up with his covers. So I asked him, "What are you doing?"
He said, "Nothing. Nothing."
I told him, "I know what you were doing and if you don't tell me then I am going to tell Daddy."
That scared him so much that he said, "Please, don't tell Daddy."
I said, "Then tell me what you were doing then and I won't say anything."
He said, "You said you knew what I was doing so you tell me."
I told him, "You were jacking off weren't you? And I will not tell Daddy if you show me what you were doing as you jack off."
He said, "I don't think that is a good idea."
I told him, "If no one can hear you then it will be ok."