I am in my bedroom practicing for a streaming tournament I have coming up. You're moping around the house not knowing what to eat because our step mum has gone out for the night and isn't around to take care of you. So you've come to annoy me, your step-sister. I am not happy. You bugging me is making me lose at my game. I'm so angry and frustrated I pause my game and turn round to confront you. Only to realise you're staring at my thong peeking out of the back of my trousers. I'm furious. You think you can handle me? Guess again. Since you've so rudely interrupted my evening I think it's only fair I should get to have some fun with you. I order you to take your dick out and show me how hard I've made you. Don't be shy, you know deep down you want to give in to my every command. You obediently oblige and present your cock to me for inspection. I tell you exactly how to stroke it for me. I want to see how big and fat you can make it. As you stroke, I slowly unbutton my shirt and show you my tits. You can't believe your luck. You've thought about this moment for so long but never dared think it would come true. Your balls are so heavy and aching, you feel them tighten even more as I slip down my trousers and put my thong on full show. I taunt you with how much I know you want it. You want to bury your face in my bum cheeks and inhale my thong deep. Finally you can take no more of my filthy mouth and wicked mind. Your dick betrays you and you finally let go and cum all over my bum cheeks, spraying ropes of your thick, sticky allover them. I'm proud of you and the mess you made. You think you claimed me, but I own your dick now and I'm not afraid to let you know as I taste your spunk on my lips. This is our little secret. You're mine now.