Convinced My Innocent Sheltered Step-Sister To Make me Cum Whenever I need it

So, I've been dating this hot prude girl Jenny. Things almost got where I wanted them and she got to nervous and she went home. So, tying to decide if I should just jerk-off, maybe try to hit up another girl, or just watch netflix. Well, my little step-sister comes down the stairs and I am glad I wasn't jerking off, she was supposed to be out with my parents! She comes and sits by me, and I can see her cute little panties. She never thinks about that stuff, she's so innocent, so naive, so...hot actually. I mean I noticed before, but not while having blue balls. Her hands would be so much softer on my cock, I decide to just be honest when she asks whats wrong. And, sweet little step-sister that she is, she wants to help, she is so nervous too, but definitely excited. She's not a virgin, but she's never sucked a cock and is happy to try with me, which is amazing, and leads to us going all the way.