Huh?

I'm coming home from circus class with Redding, Mason, and their buddy, Will Mac.  Will is coming over for dinner but is concerned that he has a lot of homework.  Redding tells him, "I'll do it for you.  Just show me how you write."  And Will says, "No, I have to bring something in.  Some kind of paper with shots on it.  Something like that."  (Which I guess constitutes a lot of homework down here.)  

"It's your immunization record," I tell him.  "Good luck with that. Your mom's going to have a tough time coming up with that one tonight."  Which reminds Mason of his own homework last spring.  "I had to do something like that too.  My mom and I both couldn't do it."  He's talking about an assignment where he was asked to fill in some kind of Mexican national record with questions that were completely foreign to us, things that are on a Mexican birth certificate that you'd never find on your own.  Mason says, "We only answered about two questions: Where were you born?  And how old were you when you were neutered?"  

Reddy chimes in, "Dad's neutered, isn't he?"  Redding will be twelve in November.  I think it's time for the talk.