All characters are over the age of 18.
My son put his cock in my mouth last night. I wasn't sure he was going to do it but I decided early on to just let whatever happened happen.
He had said, "Hey mom, I'm gonna fuck your mouth."
Obviously, this was quite surprising. My son had never said anything quite so vulgar. And men being men, I figured, maybe he's just being ridiculous and outrageous for fun.
So I acted shocked in the best way a mother can. I covered my mouth, gasped loudly, looked up at the ceiling and back down into his eyes and said, "You? My own son? You're going to fuck your mother's mouth. With your cock?"
He brightened up. I'm sure he had no idea I would be so playful about it. The whole time I'm thinking "hah, buddy. you have no idea how much cum this mouth has tasted."
So he got his wits about him, and in real-time he changed his approach.
"Yes." he said, serious all of a sudden.
"I'm going to fuck your mouth. You're going to sit there, on your knees. And I'm going to wrap my hands around your soft little head. Maybe I'll even smell your hair first. Maybe I'll even kiss your lips. But then, when I'm ready to cross that line... yeah, then, I'm going to put my cock at the entrance to your mouth. I'm going to push it in, feeling the wetness of that inner area being broken with the outside world. That orifice made to project into the world your aims, your goals.... NO. It will be plugged. It will be cut off. It will be silenced. By your son's hard cock. I will completely occupy your language conveyer with my shaft of lust. You will only make the wet, sparking sounds of spit being forced into every crevice. I'm going to use you. You are my toy. My toy to use for the express purpose of making my cock cum."