If someone has joined your playground session and you don’t want them to be there, or they’re getting on your nerves by not listening to you.
You can only kick players if you are the host.
In order to do this, you should lick the options button on PlayStation and then click on there banners name. If you are host, there will be a kick option.
This will kick them from your session, and they shouldn’t be able to join back.
If for some reason they do join back your best option is to back out of the game and set your party to invite only instead of public.
If they are somehow still joining after this then someone ese in your game must be inviting them.