Growing Up

A fond memory of mine is while growing up I didn't get much alone time unless while showering. So as a horny teen growing up the shower was the best place to jack off. Now I used to spend a lot of time in the shower and thinking back now I reckon my older sister knew what I was up to. Anyway this takes place in the shower I had been going for a while now just slowly pumping away. The hot water and steam rising the naughty thoughts about some girl getting me very excited. Was all to much as I had not heard my sister barge into the bathroom. She asked what I was doing even though she already knew. At the time she said something I had stopped but her staring at me quickly made me more excited. I decided to just keep going while she watched. I knew I wasn't far off so as I pumped my dick faster now I ended up blowing my load on the glass as she watched. Once I had finished she left the bathroom. We have never spoken about this incident at all.