I started jerking off when I was 11 or 12. It was like the greatest discovery in the world. (Well, until I discovered sex with girls, but that's another story.)
One long weekend, my family went away with a two other families to a house to go skiing. I was 13, and there were two girls, both 12 who were along on the trip as well. The mother of one of the girls was in her late 30s and was really hot.
After skiing one day, several of us were hanging out in the hot tub. It was all the kids, and I was the oldest. The two 12-year-old girls were there; one had already developed nice breasts and her friend, while still relatively flat-chested, had a tiny bikini on, that kept slipping. I don't know if the girls were teasing me on purpose, but I was definitely getting hard in the water. I couldn't take it much more, so I had to leave and jerk off.
I went down to the bathroom near my room. It was near the girls' room, and since I knew they were up in the hot tub, I snuck in quickly to grab a pair of panties. I think it was the first time I'd ever done such a thing. My cock was rock hard, and poking out the front of my bathing suit.
I ducked into the bathroom, whipped my shorts down, and sat on the toilet, stroking my cock. I held the panties in one hand, feeling them sort of satiny and trying to catch the scent. I was horny and hard, and it wasn't going to be long before I came.
Then the door handle started to turn. I was shocked, and I froze. The door opened, and it was the hot mom of one of the girls. And there I was, my hard cock in one hand, and her daughters' panties in the other!
She put a hand up to her mouth in surprise, and that was all it took. My cock spasmed, and I shot several thick ropes of cum up in to the air and onto my stomach. It was such a hot orgasm, my toes curled and I almost saw stars... But the mom looked me in the eye and gave a little half smile. She didn't say a word and backed out of the door.
For the rest of the weekend, I tried to avoid her, but she didn't treat me any differently.
From then on, though, I loved the idea of getting caught or being watched by girls when I masturbate.
Let me know if you like the story. Thanks!