Seducing my step-dad

I am home from college for the summer and i can hear my step-mom fucking my step dad every night, she screams so loud, i don't get what the big deal is, but i want to find out. i catch him in the living room alone while my step-mom is in bed, and i confront him about the noise, he is shocked but i continue to talk about how the boys at college don't fuck me that hard. i can tell he's getting turned on, i show him my tits and then i take my shorts off for him and convince him to get his cock out for me. i jerk and suck my step dads big cock and then ride it reverse cowgirl and then he fucks me missionary and gives me a big creampie. a few days later i can hear noises again and then i notice their bedroom door is open and i listen to them talking, my step dad wants to fuck my step-mom's ass but it is too tight, i think this is my perfect chance to join in. i go into the bedroom and tell them my step dad can fuck my ass instead while my step-mom watches! he fucks my ass while my step-mom masturbates and watches him give me a big anal creampie.