Quality time with my son

Adam seemed to have been disappearing quite a bit lately, doing things in the garage on a daily basis. He was out of school, and I knew that it was hot in the garage in summer. I wondered why he didn't spend more time around the pool like the rest of us.
One day, I decided to investigate.
I waited until he had been in the garage for about ten minutes, then I carefully opened the door from the kitchen. The garage light was on, and surprisingly, it wasn't extremely hot, just a little warm. I couldn't see Adam anywhere. I heard a muffled noise from behind a row of shelves that my husband had installed a few years ago, and carefully crept over to the end of the shelves.
Adam didn't see me, and obviously hadn't heard me open the door. He had no idea that I was there. His back was to me, but I knew that he was masturbating. I could see the rhythmic movements tightening his back muscles as he sat, facing the garage door. His shorts were pulled down to his ankles, and his knees were drawn up.
The sight shocked me at first, but strangely it excited me also. I couldn't see exactly what he was doing, but I knew he was jacking off. I felt a stirring in my crotch. Something that I hadn't felt since my husband Jack had left us for another woman almost two year before.I felt disgusted with myself, I was getting turned on watching my son jacking off, something that I knew teenagers did. I knew it was normal, and that what I was feeling wasn't.
I just stood there, wondering whether to go upstairs and finger myself to a mind-blowing orgasm, or finger myself as I watched my son's muscular back tighten and relax and his arm moved slowly up and down his cock.
I wanted a better look, a good, close-up look at his cock. I knew that it was wrong but the sight of my handsome teenage son in the throws of passion made my mind numb, and my body so aroused that I couldn't help myself. He was only 18 and couldn't help what his hormones were doing to him. I had turned 43 not three days ago and should have been able to control mine.
I reached inside my pants and found the elastic band to my undies. I reached into and rubbed my fingers over my bush, shivering at the luscious feeling of sinful pleasure, then I parted my cunt lips with my fingers, imagining my son's erect cock thrusting in between them. I moaned involuntarily, and Adam suddenly whirled around toward me, a look of terror on his face.
"Mom! What? What are you...?"
He was facing half toward me; I could see his hairy balls nestled between his legs. They were two large orbs surrounded by a fleshy sac speckled with dark brown hair. The skin was stretched over the orbs. The warmth in the room must have made them hang low between his legs, I thought.
I guess the sudden interruption and the sight of me standing there like that shocked him. He froze for fully thirty seconds, staring at the twitching movement of my hand in my pants. I knew that I should stop this perverted display of my lust; that my son would never again be able to think of me as before.
Then I gasped as he reached down and touched the purplish head of his dick. I couldn't see it very clearly, but it was glistening from pre- come that his manipulation had coated it with. He looked into my eyes as he swirled it around the head of his dick.
Then he put his fingers around his cock and began to stroke it. I couldn't stand the sight of him doing that, it was making my so hot I thought that I might faint. I began to really finger myself, I pulled my pants all the way down to my ankles and inserted one finger into my cunt and began to really finger myself hard, another moan of pleasure escaped my lips. "Adam," was all I said.
He turned fully toward me and stood up, his shorts around his ankles. His hard cock stuck straight out at me, framed by a mass of pubic hair.
He stood open-mouthed, staring at me, at my fingers that I kept rubbing myself with even though I knew it was so very very wrong.
"Take them all the way off," he said, his voice husky.
I stared at his fat cock, which was sticking straight up at me and throbbing in time with his heartbeat.
I kicked off my loafers and then stepped out of my shorts and panties, then took off my halter-top. My clothes now a pile at my feet, standing in front of my naked son, staring at his throbbing cock that was pointing up at me and seeing the look on his face, I was so excited and so very frightened.
"God, Mom, you're beautiful," he said. His voice was soft, and the look in his eyes was gentle, but filled with lust.
"Uh, you're pretty handsome, yourself...I..." I stopped masturbating as a rush of guilt submerged my arousal.
He shrugged. "I don't care, Mom."
He took off his shirt and stepped out of his pants and shorts. He looked at me.
"Suck me," he said.
I was shocked, crushed. My son shouldn't have said that to me, it was something that I had caused by my lewd display. But to my shame I wanted to.
I took a few steps toward him and knelt between his legs. His cock was right in front of my face. His big balls hung low, and I reached up and cupped them in my hands, running my fingers over the velvety soft skin. I put my tongue right at that place where his cock met his balls, in those little folds of skin left wrinkled by the cock pulling the skin upward.
"Hey, lick my balls Mom, that's great, wow," he gasped. Shamefully I ran my tongue across one veined, hairy part of his sac, feeling the moving, egg-shaped orb beneath my tongue. Then, I did the same to the other half of his fuzzy nuts.
I licked his thigh, then moved back to his hairy balls. He was moaning, telling me how good it felt. The salty taste and the feel of his balls in my mouth were too much for me. I reached down and began fingering my clitoris as I continued to suck off my son.
I looked up at him as I licked his balls as I did it. He was looking down at my face as my tongue repeatedly darted out, tasting the skin around his cock.
"Oh, God, Mom, what a sight!" Adam said.
I moved my tongue up, licking the shaft as I went, feeling those big purple veins on the tip of my tongue. I licked all the way to the big, throbbing purple head, and just opened my mouth wide and took him in as far as I could.
When it reached the back of my throat, I swallowed hungrily, tasting his dick. It was just like when I'd done it to my husband Jack, he felt and tasted just like Jack. I wrapped my hand around the base of his teenaged cock and stroked upward gently. He grabbed the back of my head and thrust his hips forward, choking me with his purple-headed monster. (Just like Jack used to do.)
I plunged one finger into my cunt, and I shivered all over as I came. The dirty image of my own son fucking my mouth in the dirty garage just put me over the top and I convulsed as I had the most intense orgasm I can ever remember having in my life.
My son groaned, pushing his cock even further into my throat. I felt the first jet of come down my throat. Then spurt after spurt filling my mouth. I swallowed most of it, but some of my son's come ran out of my mouth and down my chin. I looked up at my son, my face full of come.
Finally, he pulled his still-throbbing cock out of my mouth. I still knelt in front of him. He reached down and pulled me up to stand beside him. I was breathing hard, and I could feel his hot gasping breath on my cheek as he turned toward me.
"Wow, Mom, that was something else!" he said. He reached over and touched my cheek, turning my face toward his. He looked down at my tits, and with one hand, reached over and gently stroked my hard nipples.
I nodded. "We've got to try that some more," I said weakly. "Is that OK with you?"
He frowned, and then smiled in his joking way. "OK," he said. "You talked me into it."
After that, I always helped Adam with things he had to do in the garage.