I know my step-daughter and her new boyfriend she met in college this semester fool around. I would expect that given their age and how crazy their hormones must be right now. She knows I approve of her sexual expression so long as it is done someplace other than my home. I am proud to know she practices safe sex, always with a draincoat, you know, those funny looking rubber things that catch the drops and glops from an ejaculating cock. As open as we are about sex in our family I just don't want to hear my step-daughter moaning and groaning in my house. The thought of hearing her sex noises skeeves me out. You can imagine my surprise when I'm putting her laundry away and find her naked boyfriend in her bed. She passed me in the hall in quite the hurry saying she was on her way to the store. Now that I see this young naked guy I understand what was about to happen under my own roof! Hmmm, so how can I prevent this hormone driven coupling from happening? If my calculations are correct, it will take Ashli about 7 minutes each way to the store and back. This gives me just enough time to grab ahold of this wanna be pussy stuffing dick and crank out his cum before she returns with the condoms. I tell him what a schmuck he is for staying there and sending my step-daughter out to fetch the draincoats. He's gonna drain alright, right into his girlfriends step-mother's hands. I'm on that cock and cranking away before he can refuse. I don't know of any horny guy that would refuse a good cock cranking anyway. This certainly is not what I had planned to do with my day but when opportunity presents itself, ya have to make exceptions. He sure has a lot of build up in those filled firm balls. I can tell by the way he moves his hips as I stroke him that he would much rather be pummeling my little girls pussy but he's not complaining about this dick service surprise either. I taunt him by telling him how much I would like to hop and bop on that big pole of his cause lord knows I don't get any action from Ashli's step-father anymore. I can hardly believe how good his big stiffy feels in my hands. I spit on it and stroke away, determined to drain those young balls of his. After a good time is spent fantasizing about what his shaft would feel like drilling my pussy while I'm fervently stroking, I tell him its time to give his cum to me. I tell him I want it all. He is not going to inject my daughters little hole today, he is going to fill my fingers with his goo. After much encouragement, he lets it all go with a great sigh of relief. I tell him to clean himself with some tissue and not say a word of this to Ashli. It will be our secret and if he wants more I will give it to him if he can come back without her knowing. I know it was a dirty thing to do to my step-daughter. The ultimate cock blocking but hey, she knows my rule of not fornicating under my roof so I figure she will just have to rub one out on herself now. I hope her boyfriend does come back for more Step-Mom action cause next time I may just mount his big dick. If anyone is going to have sex in this house, it's gonna be me.