As interesting as you statement to say "why u lukin at ma crotch u gay fool?!" is, I wouldn't suggest it. just makes a person sound childish and opens up a window for much more.
There are many ways of hiding an erection as some have given above. Give them a try and keep your mind busy.
Just remember, your just a normal healthy male, and also remember other people your age are going through the same thing as well.