Kinky fuck story with stepsis

My stepsis wants to enter this popular sorority and they asked her to make a picture with her face and someone's dick in it as a part of her trial. The next day they gave her a new task – to make some videos of her sucking my dick and she came up with a perfect blowjob performance. She got accepted and let me fuck her as a thank you for giving her a helping... uh, well, dick. Boy, what a pussy she has and now we fuck all the time.