All characters in this story who engage in sex are over 18 years of age.
It was my apartment, I lived there alone, so there was no reason I couldn't jerk off on my bed with the door open.
I didn't hear mum come in. She has a key, she usually calls before she visits, but today, being my birthday, she had planned to surprise me. I don't think she had this particular surprise in mind though.
So there I was, watching a milf getting licked out on my favourite incest porn channel, and so ready to cum. I was on my back, I was gonna blow on my stomach before I had a shower. A few seconds that changed my life were approaching.
Picture the scene. I'm so close to cumming that nothing was going to stop me. I catch movement in my bedroom door. Mum is standing there, a shopping bag in her hand, and my cock erupts into the air just as I look towards the door. Straight into mum's eyes.
She was clearly shocked, but here's the thing: In the five seconds or so of my ejaculation, her eyes spent four of them watching my cock spurt. It's frozen into my brain forever. Mum in a light blue v-neck cotton dress, dark blue little flowers printed on it, thin straps over her shoulders, a small amount of cleavage showing her ample chest, a conflicted look on her face as she watched - not 'saw' but 'watched' - her own son ejaculating.
I could have rolled over, covered myself, whatever. And she could have closed her eyes, spun around and moved away from the doorway. In those few seconds, we both allowed ourselves to admit something we had always known about each other. But that was still to come in the hours that followed.
As I squeezed the last of my jizz from my knob, mum did indeed turn away. I called after her: "It's OK mum. It was an accident."
I showered, dressed, and went into the kitchen. She was fussing with the contents of the shopping bag. She was blushing, and said: "Um, happy birthday Tony. I guess!"
I smiled as she looked away, unable to hold my gaze. I spoke: "Mum, it's OK. You didn't mean to, and I..."
"Stop, please Tony."
"If you don't want to talk about it, I understand mum."
"No. You don't. You're my son."
I stayed silent. She was selecting her next words.
"You're my son, what you were doing is perfectly normal and natural, except... Shit!"
She looked directly into my eyes.
"Tony, I'm no teenager. I know what I felt, and you felt it too. I could see it in your eyes."
I gulped. She was braver than me.
"What are you saying mum?"
"Tony, you were watching me while I was... watching you. We both know it. And you're my son. This would be a funny anecdote if not for that fact."
"I don't follow."
"Tony, I should have... I could have just turned away but I wanted to see you... finish." She stopped what she was doing, hands flat on the bench, her head bowed.
I tried some humour to lighten the serious atmosphere: "Well, it's not every day you walk in on a young guy masturbating! Maybe you just couldn't help staying for the finale!"
"Maybe." She was smiling, then she got serious again: "But you're missing the point. I'm trying to tell you... Um, Tony I wanted to see you finish because it was you. My son. Do you understand now?"
I thought I did, but my mind was racing through all kinds of confusion right then.
"Um, how did you feel when... when I came?"
"That's my point Tony. Come here for a moment."
My wooden legs somehow covered the distance. I was a robot, I had no sense of what was happening, and then suddenly I was standing face to face with my mother, she had lifted the hem of her dress and put my hand inside her panties. I gasped.
"That is how I felt, baby. Oh! Oh god. I'm already...gonna..."
She was warm and wet around my index finger, and I felt her shudder, heard her pulsing exhalation of breath, and my brain recognised that my mother had just had an orgasm with my finger inside her pussy.
In that instant I was raging desire. I had to have her. With both hands I reached under her dress and pulled her panties down her thighs. She stopped them half-way to her knees: "Oh no, baby, wait!"
I couldn't. I tugged at her panties. She held them firmly. I got to my knees and tried to pull them down, still she held them. I backed her up half a pace until her ass was against the kitchen table. She had to put one hand behind her for balance, the other still held her panties up. I gave up that assault and lifted her dress, instantly burying my head between her partly-closed thighs.
"Oh no, Tony. Don't! Please don't!"