First Time in Grandmother's Bathroom

I was either 9 or 10, my cousin John use to tease me saying that I jacked off and in fact I had never even thought about it. I really didn't know what it was about. Anyway, I went to my grandmother's that day after school. I was in the bathroom and decided I would try it out. I am uncircumcised so I didn't need the aid of lotion. I just started stroking my penis up and down. I went slowly for about 15 minutes it was feeling good but I still didn't see what was so great about it. So I continued to stroke away this time a little faster and it started to feel great. After a total of about 45 minutes I was about to scream with excitement. My penis was rock hard and throbbing. I forgot about everything I was focused on my penis and the way it was feeling. One problem: I didn't know what cum was, I didn't know that at some point I would climax and cum. Well, that time came and I was cumming and it kinda had a stinging feeling. My stomach was feeling uneasy, so I swore I would never jack off again. A few days later I was back at my grandmother's and all I could think about was touching my penis. Well, I finally gave in and I was in the bathroom jacking away this time it took me about 20 minutes and I was cumming and it felt wonderful. I would visit my grandmother's three to four times a week and I would always pleasure myself every time.