StepMommy Will Never Know

You know your Step-Dad's been cheating on your Step-Mom, you suspected it for a while and when checking his phone your suspicions were correct. You love her so much, she could do so much better than that wanker.
One night you overhear your Step-Mom begging him to fuck her and he declines, just when you thought his behavior couldn't get any worse. There's nothing you want more in this world than to see step-Mom happy again, she's lost her sparkle because of that loser Step-Father of yours. So you come to the very fucked up decision to sneak into their bedroom, she is so desperate for some love and affection she won't even realize it's you. Despite noticing that you have grown, she loves it so much she doesn't even bother to turn on the lights. She is gagging for your cock, you're a little bit reluctant to slip it inside of her though... maybe that's too far. But when she reminds you that she is fertile right now and her and your Step-Dad are meant to be trying to get pregnant again, you can't resist. The thought of impregnating your Step-Mother makes you throb. You explode for Step-Mommy, and she goes off to bed completely unaware of the extremely taboo sex she has just encountered with her boy.
Now you have had a taste of Step-Mommy's forbidden pussy, you can't get enough. How will anything ever compare to this, not just the taboo of it all but to finally see Step-Mommy happy again makes your sneaky antics totally worth it. You just hope that she never finds out about this, surely she wouldn't want to be in a romantic relationship with her step-Son over her Husband?