Step-mommy mistakes you for her husband

I came home horny and when i see someone laying on the couch i assumed its my husband. i take my clothes off and sit on his face but funny enough it feels a bit different, he is using his tongue something he never does but i like it to much so i dont have to question it but when i am about to sit on his cock and ride it i discover its my step-son, im upset he tricked me into thinking its my husband but now i am so horny that i wanna continue fucking him .