You were watching porn, while I, your sis, suddenly entered the room and sat down at the sofa right next to you. I instantly understood, what you are doing, and made you show me, what kind of stuff you are into. To my surprise you were watching brother-sister porn, and first I didn’t know, how to react, but then I realized that my shorts got wet of thinking about it. So I decided to join you. It is not forbidden to masturbate in same room, if we are not touching each other. There is nothing wrong, if we are only watching. So let me see you jerking off for me, and watch me soaking my shorts and sofa all and over.