I was reading the thread about ever getting caught fapping then I began to wonder why I was never caught by my parents.
Then I remembered that while fapping I sensed ANY kind of disturbance my boner would like do some weird debonizing shit and completely go away for like five minutes or until I identified the source of the sound.
When i look at that really ugly girl picture in one of those "Would you fuck it" thread. That turned me off in less than a 3 seconds. In fact, i fell off my chair with the chair.
No I never did have such a useful tecnique. There was that one time though when I had to babysit my lil brother when he was still a little baby. I was fappin away that day and was about to cum and then he started screaming like crazy. So I run over to him and held him for a while. The boner died like 8 seconds into that.
I can be VERY into it (like about 2 seconds to actually cumming) and hearing someone walk up the stairs, even CLOSE to my room INSTANTLY makes me lose it. I can't lose it whenever I want, although that would be an awesome talent to have in public areas.
Getting aroused requires you to be relaxed. If you're tense about getting caught, and you do hear something suspicious, you trigger some stress signals.
Your boner will die within seconds of being nervous. I'm sure your body thinks it can use that little extra volume of blood elsewhere.