There was a T.V. show called Dinosaurs. The baby called his mother The Mama and dad Not The Mama. For months Gus wouldn't let me sleep so one day I told my family I was giving him away (almost completely kidding

). So they "took" him. Later I went to take him out to play and they started teasing me saying he wasn't mine anymore. I took him saying they weren't his mama, I was.
So I became The Mama and everyone else is Not The Mama.
We also use the line, "I'm the baby, gotta love me" when he's being bad.