There is no such thing as a friendly competition in my opinion. Simply because I believe that when you have a friend that is in someway finds themselves competing with you. Secretly that means they have a desire to see you beneath them. They have a drive to be the so called special one, they want something that everyone sees and knows about you, that they know they don't possess. To me, that can grow into envy and then jealousy and as my mother always say "Jealousy is as cruel as the grave." So, when you start to see this happening, depending on who your friend is, because you're the only one who may know this person intimately; try and talk them, see where their head is at, and if you know for a fact and feel that this will never change. Then, ease your hand out of the lion's den until you've completely disappeared from their existence. Better to remove yourself gracefully than to stay and try and reason with someone that will not understand you,