My parents were visiting me a while ago. Maybe a year. Maybe more. I don't really know. Anyway, we all headed out of the building so we could go have dinner at some restaurant. We take the elevator to the first floor and the lobby, then head out. Some guy is fiddling with the intercom, apparently looking for someone in the building. We walk out, and then my dad holds the door open for this guy. I turn to the gentleman and tell him,
I'm sorry, but I can't let you in. I don't know you. After which my parents get all confused and question me about not being courteous, letting him in. Guy went back to trying to raise his friend on the intercom.
I don't know if I got through to my parents, but they didn't argue it much. What amused me most was that my parents moved to Lynden when my dad retired. A big reason for that move was my mom was afraid of the crime in the city.