Master?

Here's a snippet of a conversation from this weekend:

Chris: You know how when you get your doctorate, people start calling you Doctor?

Me: Yeah...

Chris: How come people don't call you Master when you finish your masters?

Me: I'm not going to call you Master.

Chris: I noticed that Master was an option for a name prefix on a form I was filling out. I'm going to start checking that box.

Me: (eye roll)