When I first started to masturbate I was sitting on my bed doing homework like I always did. I was 13, and I was reading my science book -- must have been feeling uncomfortable at the time but I ignored it -- and my science book was ordinary like an eighth grade one. All of a sudden I felt like, my body was tingling all over, and I HAD to take off my clothes. No one suggested it or anything. I tried to resist, even tried to force myself to not do it, but it was unbearable so I took off all of my clothes. I got down on my knees on the floor and lay down prone naked and I felt like I was exploding and dying. Then I looked down and there was some cum where my penis was, and then I guessed that I masturbated and, it actually felt pretty good if I could control it.
The second time I did it I had much more control and it felt real good. Soon I was doing in regularly, almost every day, in bed. I felt more horny when I pulled my briefs up my butt like a wedgie. I started to secretly cut my small briefs up into a G-string and masturbate in them.
My sister had some sexy thong panties. I would sneak in her room and put them on once in a while. I liked the comfort and feeling of wearing her thong panties. I didn't masturbate in them because I didn't want my cum to mess them up, so I would just wear them to feel horny and then I would put my penis into something -- a sock or even a shoe or my G-string brief -- and pump my cum from my hard penis.
When I was in college I would masturbate too, but maybe only four or five times a week. I didn't have any thong or g-string panties, being religious, but I was very attracted to them.
After I got married I told my wife about my sexual urges and fantasies, and I asked her if she would buy some thong and g-string panties to wear. She would hardly every wear them, so I started wearing them. I didn't mind that she would see me, and I felt so horny while I was wearing them. They were great to masturbate in!
Now I wear them often, and I'm wearing a string bikini g-string panty right now. I have such a big semen stain that it is dripping out of the front of the panty! I wear them around the house and I will probably get caught some day. But I feel a lot less shy about it. I feel so horny in them, and I love the feeling of the strap touching my anus... and I love pulling them up my butt and masturbating until I pump my cum.