"Hello, we've come to see Mr & Mrs Smith."
"I not Mr Smith."
"No, we've come to see them, they live here."
"John and Mary? Are they in?"
"John and Mary Smith. They live here. Are they in? Can you please tell them we've arrived."
"I don't think so. Not Smith."
"Who lives here?"
"I don't know."
"But you are the Security Guard, working at this house?"
"Yes, it's me, the security."
"Can you find the owner of this house please?"
"Ah, I am not owning this house."
Sound of my head banging off the gate and Mary running out into the driveway yelling at the Security Guard. Damn sure no-one's going to get past him.