It happened last week Friday after I came home from the gym. When I walked into my house I was greeted by my sister who was wearing the infamous Nike pro shorts and a white t-shirt, and of course she looked hot in them and her ass was just so stunning. Obviously I would get hard looking at her and she noticed my boner and sayed "seems like someone's a little happy". I was embarrassed by that and tried covering my crotch but, that wasn't necessary because my sis pulled my shorts down revealing my 8in dick, which stunned her at first but she began to suck my cock till I came (which was 5 minutes). She would swallow my cum and told me "this will be our little Friday night session". I was surprised by that and luckily we were home alone for only a few minutes before our mother came back home.