A thing for the forbidden

You and Anna have been dating for a few months, she's great, fun and super intelligent. Her sex drive is ridiculously high, its quite unusual but hey your not going to complain. One evening after a particularly gruelling work week, Anna comes into the bedroom dressed in sexy new lingerie. She starts to flaunt around in front of you and your cock begins you waken up for her. She sucks you so good, the things she can do with her tongue is wild. You flip her over and climb on top, thrusting into her hot wetness is already making you feel better. She climbs on top and rides you, your so deep inside her and she begins to cum hard. As she is cumming, she tells you she loves you. With your orgasm building up, you close your eyes, and murmur 'I love you to step-mom' STEP-MOM? Step-mom?! Wtf. What a ridiculous time for that to slip out. Anna laughs and climbs off. Your embarrassment is clear and you tell her you are tired. Intrigued the next days Anna checks your laptop. She finds your browsing history and clicks on your MILF porn. Interested, if this could spice of your sex life she has an idea. That night, Anna gives you the 'look'. She's never satisfied, this girl. She asks if you think she could pull 'milf' off. Your nervously laugh, asking where this has came from. Leaning into kiss her you try to shut her up. Your head is inbetween her legs and she asks if you want to taste her milf pussy. What the hell is wrong with her? Nervously you mutter 'yeah'. Emboldened by your participation she gets on all fours asking you to fuck her. OK weird, you ignore it, this girl is seriously kinky. Bent over, taking your cock deep, she moans loudly, cum for your stepMom! WHAT the hell, you explode inside her but jump back asking what the fuck she is playing at? She's gone too far. You confront her and she laughs it off, telling you you're over reacting. You retire to the couch. The next day you visit your stepMom's for dinner, she probes, knowing something is up. You shrug it off. How can you explain to her that your girlfriend wants you to call her stepMommy? Watching your stepMom make dinner, you begin to daydream. She has the most perfect ass, the fullest perky tits. Why are you looking but also, why have you not seen this before. Watching her wiggle her ass you are hearing Annas voice over and over again 'cum inside your stepMom'. The next morning, She is coming out the bathroom and she lets the towel slip. it would have been innocent if Anna has not already planted these damn thoughts in your mind. Sat on the sofa, you tell her everything, leaving no details out. Watching her take in your story your mind starts to wander again. stepMom is furious she cannot believe Anna has put you in such an uncomfortable situation. She leans into kiss you innocently, but there is something lingering. She lingers too close and you both make out. Before you know it your own stepmother has sucked you off and taken a facial better than Anna ever does. She next day, guilt ridden stepMom tries to make sense of it all, but all she can makes sense in her head is that she wont let that poisonous girl ruin you. If you have a thing for MILF so be it, but it wont be her.