This happened when I was 17 years old. I was in my bedroom naked, stroking my cock on my bed. Suddenly my mother comes into the room and we both freeze. My cock is still in my hand as she sort of looks me over, shocked and then a small smile comes to her face, mutters a sorry and she turns and leaves.
This made me incredibly horny, needless to say I finished myself off rather quickly afterward. I wanted to be caught again so I let a similar situation happen, she came in again, but this time I kept stroking as she was looking shocked, and I came all over my chest as she watched. She got a huge smile on her face and turned and left. Since that day I have never made an attempt to cover up my stroking but somehow I was never caught again!
Definately would love to though.