The difference between little and big

Brayden thinks he is a big boy now and should always be referred to as such.  For example, I will say "Brayden are you my little buddy?"  He responds with "no Daddy, Brady big buddy."  So like the bad parent I am, I have started to mess with him.  "Brayden are you a little knucklehead?"  Again the response "no Daddy, big knucklehead."  These can go over for extended periods of time until he gets really frustrated.  Funny little things he does that make me laugh.