StepBrother & StepSister: Reintegration

You've just gotten out of prison after serving years and years for a crime you didn't commit. You're still coming to terms with what you lost, what you missed out on. Your stepsister took you in, offered for you to stay with her and her family as long as you need to get back on your feet. Now you find yourself sat in her living room, looking across at this beautiful woman who's stayed up late just to catch up with you and you're confused. She's your stepsister and you love her for all she's doing for you, but there's something else. She stopped visiting you after a while and it's the first time you're seeing her face to face like this in a long time. Prison was lonely. It's been a long time since you even interacted with a woman, let alone since you've "been" with one. You're getting turned on and you know you shouldn't. But her kindness, her comforting words and... her huge breasts are making you feel things. You start to stroke yourself right there in front of her as she tells you about her lacklustre sex life with her husband who's in bed upstairs and the look of shock on her face makes you want to stop, but you can't. Suddenly, this all consuming desire and lust for this woman has taken over. She tries to look away, tell you to stop but to your surprise, she seems to be feeling it too, and starts to play with herself. She tells you it's wrong but she feels to guilty to stop. You've been without for so long, you deserve this. You both do. Just please, please don't ever mention what happened tonight?