The games you have received from PS+ are essentially tied to your account like any other purchase, so unless your account remains on the console, and maintains an active PS+ sub, he won't be able to play them.
However, if you don't mind leaving your account on the system, he can just make his own new account on that system, and still play your games as long as your account has not been deleted or deactivated from that console. The PS+ games will still only remain active as long as your account maintains a PS+ sub.
Apologies if my answers seem a bit convoluted, I'm running on no sleep today.