Hi MoonGlow - and welcome and thanks for sharing.
My thoughts.....just let it "grow". Don't over analyze it, don't label it, just live it.
It sounds like your two guys are getting along fine and they are definately old enough and mature enough to see what's developing. And apparently it's quite comfortable for them.
Be open to questions as they come but I wouldn't "force" big philosophical conversations (your fear of scaring your men etc). Just let it flow and develop and try to educate yourself on some of interesting twists that may arise. Because I'm sure they will and as you can read here and other places, the turns can be navigated successfully. The better prepared you are the easier they are to navigate.
Good luck and above all - ENJOY !