Clarification question first: On the nights to do as you please will you switch off who has your 6 year old so the other can go out?
If so, I might suggest 3 Family Nights, 1 night just you two, 1 night for you to do as you please (no kiddo) and 2 nights for him to do as he pleases (no kiddo). I know that might seem unfair but I'm putting it in the context of him having two other people he's dating while you currently have none. Of course if your dating status changes the schedule might need to change too. And as the parent of 2 kids the idea of one night every week to do as I please sounds heavenly! Right now I might manage twice a month, but once a month is more likely. :-P
Pan Female, Hinge in a V between my mono (straight) husband, Monochrome and my poly (pan) partner, ThatGuyInBlack