One Subscription Two Houses

The short answer Yes, yes & no. The long answer is yes you can log in on another console with your account and play the games you have on another console, including fortnite. No, you do not need another subscription, subscriptions are tied to the account,
not the console.

Thanks for the response. I thought that might be the case. That's too bad. No way I'm paying for two subscriptions in one house lol.

Thanks again

And this won't remove the subscription from my son's console, right?

Subscriptions are tied to the ACCOUNT that bought the subscription.

So your son can go to any console in the world, sign in there, and he will have access to his Gold membership subscription, Game Pass (if applicable) and digital games.

As long as he's signed in on a specific console, that console will also share the Gold membership to anyone playing with him on that console. Even if your son is not actively playing, as long as he is signed online (for example on a second controller), another
person can play on that console and access his games and benefit from the Gold membership.

The account that owns the subscription, can designate one console as their "Home Console" (or as you call it the "Main console") and will share the Gold to that CONSOLE. Any previous "Home Console" will lose the ability to share Gold and games when your
son designates a new Home Console.

Your son's account will still keep his Gold membership, and will share it to the designated Home Console, which in turn allows anyone on that console to benefit from your son's games and Subscriptions.

So is there a specific reason why you want to keep your son's console the Home Console? Are you (or someone else besides your son) playing on that console and needs the subscription?

If so, then there is no other way around than to buy a separate Gold membership for your girlfriends kid. Or you'll have to play on that console to benefit from the shared Gold membership after setting the "girlfriend console" as your son's Home Console.

ok this is how you go about it. first off does your son have gold already on his account and have digital games on that account? if so set up the new xbox like normal make a account for your ladys kid. when that's complete on the new console go to settings....
personalization... then click my home xbox. form there you will put your sons account as the home xbox account for the new console. from that point on the new console should have the xbox live and all digital games from the other account.

Ill try that again when I get home. I have tried every iteration of switching accounts, setting who's console is 'home'... you name it.
It always makes me choose one console over the other. Whats the point of even having two consoles if you can only play one at a time?

I miss the good old days of just enjoying playing games without accounts, internet access, subscriptions, lagging connections, constantly patching and updating, etc...