It's the night before your sister's wedding and she asks you to hang out with her, saying that she doesn't want to be by herself. Your sister is obviously anxious and deep in thought about her wedding tomorrow, when she asks you the question, "Do you think I'm making a mistake by getting married?" You honestly think she is. You've never liked the guy she is engaged to. But, you tell her that she is the only one who can make that call. She sighs and starts telling you about how she has had doubts about this marriage for weeks now. She doesn't want to give up her freedom. She doesn't want to move into his house. And, she doesn't want to not have anymore firsts and just experience the same man over and over for the rest of her life. She says that maybe she would feel different if it was someone else, someone she truly loved, but with her fiancee, she doesn't want to just fuck only him forever. You blurt out that you think that maybe she should have one last sex escapade with a new guy tonight. She giggles and says she was thinking the same thing. But, who would she find on such short notice? She doesn't want to go to a bar and find some random dude to fuck. That's when you say that maybe it should be you. Maybe the two of you, brother and sister, should have sex with one another. She's taken aback, but clearly happy about what you just said. She then admits that she has had a crush on you for a long time. After all, you are her big brother. You've always been there for her, there to protect her and take care of her. And, she has always thought that you were the most attractive man she has ever seen. That's when your sister begins to unbutton the top of her dress. She teases you with how she knows you've been wanting to see her topless, to see her naked body, just as bad as she's wanted to see your cock. Your dick is already getting hard from all this, something your sister has noticed. Soon, you're taking your dick out of your pants, much to the delight of your sister. Your dick is the biggest cock she has ever seen. Much bigger than her fiancee's. She needs you, and she needs you right now. Your sister starts off on top of you. Slowly rubbing the head of your cock on her clit, teasing both you and herself. It's not long before she is riding you. It's so hot, it's so naughty, it's so taboo, what the two of you are doing. That alone would make this feel perfect, but it's not just that. The two of you go so well together. Even though you are brother and sister, as she is bouncing up and down on your cock you both know that you two are meant for one another. She shouldn't be marrying that other guy. She should be marrying you. You're her perfect big brother. The best sex she has ever had. The most amazing guy she has ever known. As your cock continues to slide in and out of her tight pussy she says that the two of you should run away together. Start a life away from everyone you know. The two of you can get married, and no one would know that you two are siblings. It would be your naughty, hot secret. Both of you are beginning to get closer to cumming. You lay her down on her back and get on top and begin to pound into her in this position. Seeing her like this, seeing your little sister in so much pleasure because of the way you are thrusting your throbbing cock into her, it's the most perfect sight you've ever seen. And as you both cum together, as you feel her pussy tighten up around you in an intense orgasm, you are so happy that you get to have this every day for the rest of your life.