Back when I was about 13 my parents had this Oster back massager. It was one that attached to the back of your hand. I saw it and being 13 was curious about it. I turned it on and turned up the speed all the way. The vibrations were intense and I thought it was neat but turned it off and put it back on the table.
A day or two later my parents had left me at home alone for the day while they were at work. I was bored and had an idea. What if I put the back massager on my penis? So I ran upstairs into their room and dug around until I found it. I took off my clothes and laid down on the bed. I plugged it in and turned it up to high. I gently touched my penis with it by laying the rubber part that normally goes against the back of your hand on it. It was intense and my penis instantly got hard. It felt incredibly good. My penis is thick, even back then and stuck straight up too.
So I kept it there and laid back to enjoy it. It was only a minute or so and I felt strange but really good. My body tensed up and my hard penis pushed against the massager. My balls tightened up and my penis began to throb and feel so good. I was having my first orgasm only I didn't know what it was. It only lasted a few seconds. I didn't shoot any cum back then. I think I did it six more times that day. It was really awesome. I think the second or third time I did it I remember precum oozing from my penis. Wow! I was able to shoot cum. I just remember the spasms in my penis going off like a machine gun when I used the massager. Like 4 or 5 pumps in a second. I would shoot cum so fast it was like I was pissing it out. Tons of it.
I still enjoy a good massager orgasm like that. I'm much older now and recently bought one of those battery powered back massagers you see. I tried it and it was fun but didn't produce the intense orgasm that my parents massager did. But it's still good!