["Well, maybe you shouldn't have taken the job then!" isn't a nice thing to say, is it... She's tempted though.] Maybe they're just trying to make sure you take your job seriously.
But that sounds like something you need to speak to them personally about. Tell them you want to spend your free time like you used to with them, and that when you do they don't have to speak so formally to you. Even if becoming king didn't feel like a big deal to you, it might have to them. They might not know how to deal with it themselves!