|1.||down syndrome motherfucker|
When you are really pissed off at someone who is normal(not retarded in anyway) and has a slightly down syndrome look face, you yell at them "what the fuck are you looking at, you down syndrome motherfucker!! This releases stress and puts a great big smile on your face. Try it today!
No examples needed for down syndrome motherfucker. You can fit it in with just about anything.