Stepson catches his stepmother sending an erotic photo

My stepson stops by when I was sending a sexy photo to my lover. I'm in my underwear and stockings. He promises to tell everything to his father (my husband) if right now I don’t fuck him and take out my erect penis. I had no choice but to accept my son's offer. I start sucking his cock and then he fucks me doggy style. I ride his cock and then he fucks me on the countertop in the kitchen. Soon he cums on my face and promises not to tell my husband anything if I sometimes give him.