Someone who overides your birthday with their own drama which makes out you are in the wrong when it is them.
When a person pretends to do something nice for your birthday such as baking a cake, then throws a hissy fit the day before your birthday involving ignoring you for several days, then blaming you for ignoring them, resulting in said person becoming the BIRTHDAY CAKE BITCH
Someone who makes a birthday cake and then thinks they can act like a bitch to the person whose birthday it is and get away with it because they made said cake.
"Why you telling me I shouldn't be horrible? I made you a damn birthday cake",
"You're a real Birthday Cake Bitch"