Sam- You call Sam Moose because you never looked at him like a moose before Crowley started calling him that and it annoys him so much.

Dean- You call Dean Deano. You pinch his face and scrunch your nose like he is a little kid.

Castiel- Other then Cass you call him Cassie because you can but he argues Cassie is a shortened version of Cassandra not Castiel.

Lucifer- You call him Luci instead of Lucifer every day.