If your goal is to play “Robin Morningwood Adventure - A Gay RPG” from the comfort of your closet without your aunt getting a notification, then you want to mark the game private.
https://help.steampowered.com/en/faqs/view/1150-C06F-4D62-4966
Obviously, this is insufficient if you don’t want the watchful eye of Valve themselves to be upon your gaming session.
Not everyone thinks of dog, there’s a bit of a bell curve.