It's gonna hurt

Me: So, are you excited that it's almost summer vacation?
Peanut: Yes.
Me: You know, when it gets to be summer vacation your new baby brother is going to be here.
Peanut: Really? He is?
Me: Yes. Is that exciting?
Peanut. Uh-huh. (Pause). You know, it's really going to hurt.
Me: What?
Peanut: It's going to hurt.
Me: What's going to hurt?
Peanut: When the baby comes out.
Me: How do you know?
Peanut: I just know.
Me: How.
Peanut: Trust me. It's going to hurt.