*NEVER share your PSN account details with someone you do not know.
Sony has an official article about activating and deactivating your Primary PS4 which you should read here. | Scenario: If Katie accidentally/intentionally logs onto PS4 (B) using EthanXYZ999, then Ethan will not be able to logon to PS4 (A).
Other users on the system can also enjoy some PlayStation Plus benefits from that account (like online multiplayer), even if that user is not logged in.
You can however, be logged into the same account on PS4, Vita, PS3 all at the same time. You can’t be logged into one account on two PS4s. You will lose access to any subscriptions and their associated entitlements.You will lose access to your PSN wallet. What happens when you close my account?The closed account’s online ID cannot be used to create another account.You will lose access to any content purchased using the account.