He is easily annoyed and very sarcastic, especially when dealing with people lacking a normal Intelligence. Unless the visitor has proper authorization, there is no permission to enter Navarro under any circumstances.
If the Chosen One gets escorted off the base, they have to talk their way through the gate guard to get back on base. If he cannot be convinced to be a soldier in the Enclave, the base will go on alert and Navarro turns hostile.
He does not allow entry into the base with companions along.