Hey Aussie Guy,

I know that things are embarrassing, but you really do not want to switch off those boners at all. When you are still in the final stages of puberty which some guys are at your age, your penis is still growing in size. The unwanted boners are part of that growing. What those "unwanted's" do is to stretch the corpus cavernosum (erectile chambers) to continue to allow more and more blood in. This is especially true if these are rock hard.

The best suggestion is to enjoy them and encourage them as much as possible while wearing clothing that can easily disguise an embarrasing situation. Do what you can to allow your penis as much free movement as is possible. Some men will get this kind of erection well into their 20's. Good luck my friend.