Unfortunately I know nothing about D&D but I will say I think it is awesome that you taught your son how to play and that you play with your whole family! I don't think it is geeky, it is a game that you enjoy playing. In my eyes it is the same as any other game it is just less mainstream. I love that you are a proud D&D player and are passing that on to your kids! :)

I wish him the best of luck on his quest to become a DM!