How Do Parents Not Hear This

My boyfriend has three kids. Me and uim were having a conversation and his daughter goes up to him and is like "Dad, dad, dad, dad, dad, dad, dad, dad!" And he's just continuing his conversation with me like he can't hear her! I've seen several parents do this where its like everyone can hear their kid BUT them. How do you do that? Everyone else can hear, but you can't? I need answers🤣