I'm a 35 year old single mother, my partner left me when our son turned 3. Sadly we found out our son had severe autism and he was unable to deal with it. My son's particular autism manifests as common traits, especially around aggressive resistance to change and difficulty expressing himself; in fact he's mostly limited to no talk or grunts.

I've not had a serious relationship since my partner left. I've seen a few guys, but mostly they don't hang around. They don't say it, but it's almost certainly because of my son and his need for full-time care. Mostly I'm not bothered about being single, I've got good friends and I've always enjoyed masturbating. ;) It's always been enough for me.

Then last year that changed.

My son has always been big for his age. His father was black and over 6ft tall and our son is a beautiful light shade of brown. However, as my son became a teenager his size became a real problem. Whenever he had one of his episodes, often like a fit, with shouting, and flailing arms, it was becoming very hard to control him. I've collected my fair share of bruises. I know he can't help it and love him completely.

As he's got older, he's also become more aware of his body. Especially his penis, which, at 15 years old was simply huge and he insisted on playing with it or doing silly things with it. I would often tell him off if he started touching it public or at other inappropriate times.

Last year we were at home one evening. I'd just had a bath and came into the living room wearing just my bathrobe. I found my son on the sofa watching TV and touching himself. Normally I immediately react and make him stop, but this time I don't know what came over me but I stood in the door way a watched him for a few moments. He had a full erection and was slow stroking it and peacefully without a care in the world. I found myself staring at him, looking at him in a way I've never looked at him before and I knew that I was starting to get wet and very excited.

I felt disgusted with myself and immediately flew off the handle at him. I shouted at him to stop and I turned the TV off. I should have known better as it caused him distress and led to a severe episode with him throwing himself around and making noises. I had to physically restrain him, which isn't easy when he's so much bigger than me. I was finally able to bundle him onto the sofa and stop him from hurting himself.

After holding him for a few minutes he calmed down. It was then, with me kneeling over him try to catch my breath that I felt him start to rub his cock against the inside of my bare leg. His dick felt enormous and rock hard. I didn't want to stress him again so I let it go, hoping he'd calm down. It was then I noticed that my bathrobe was partly open and one of my breasts had spilled out. I saw him looking at it, just hanging there and heaving as I still breathed heavily. He had a look of pure lust in his eyes. I moved a hand to pull my breast back inside my robe, but he grabbed my wrist and held it like iron.

His breath was getting faster now as he rubbed his cock against my leg more intensely. At this point I wanted my son to be calm and safe and after a while I relaxed and started to enjoy feeling his cock push high up my inside leg, closer to my bare pussy which was now very wet.

Although I desperately wanted to feel that massive cock slide into my wet pussy, part of me was fighting against letting that happen. I just wanted him to be calm and happy, so I pushed him back a little a slid my hand onto his dick and started to gently stroke it. He bucked his hips toward me, indicating that he wanted more. I love the feel of his thick shaft in my hand and opened my robe fully, exposing both of my breasts and laid down next to him. He stared at my tits, which he'd seen hundreds of times since he was little, but this time he was looking at them differently. My nipples were now very hard as I took his enormous dick in my hand and began to gently wank him off.

I reasoned in my mind that he would never have a girlfriend and that I as his mother was the only person able to help him deal with his hormones and urges safely. As he lay there breathing heavily as I wanked him, he tried to push his cock upward toward my face. I wasn't going to let him put his cock in my mouth, that didn't feel right to me. Instead I pushed him back down, pulled up his t-shirt and made him shoot his cum all over his tummy.

After that we lay there together and he fell asleep immediately. I was still incredibly horny from what I'd just experience and I started to touch myself as I looked down his big 15 year old cock laying there and still hard. At one point as I was frigging myself and close to orgasm I actually wiped up some of his cum onto my fingers and put it in my mouth. The taste of it drove me wild and made me cum in seconds. My pussy contracted hard again my fingers as I wiped up more of his cum and spread it over my nipples -- it was enough to send me over the edge and I came so hard I literally gasped and fell back against the sofa unable to move.

In some ways this episode was the start of learning how to calm my son and pacify him. On others it has made him quick to anger if his sexual demands are not met. We've had a few encounters now that have felt a bit rape like, but I know it's safer if I do this for my son so that he doesn't hurt himself or anyone else.