#it'd be so funny to do a sidecomic for this...

[dadmareau]

Does Nightmare eventually get to see Dream grow up all over again? Will he have to deal with his son’s brother’s newfound emotions and hormones?

I suppose so, if nothing bad ever happens to Dream.

I won't be writing his Angsty Teenage Era if that's what you're asking, but anyone could do it if they so pleased. The story/blog is set to close (or 'look away') when Nightmare figures out how to leave Dreamtale and return to his world, and it won't be taking him that long to do so.