My shy stepsister is a virgin and asks me to fuck her for the first time and cum in her ass.

I find my shy stepsister a little sad, she tells me that her boyfriend has asked her a couple of times to have sex and she has not wanted to because she is a virgin and she is afraid. I advise her, I tell her that if she wants I will explain to her what it is like and I invite her to make it very rich so that she can do the same with her boyfriend. She agrees and it's the best sex of my life.