City Living: Give key to apartment?

Voltron

I don't understand how this works. I lock the door to my Sim's apartment and gave his neighbour (who is also his best friend) a key to the apartment so they could get in. They can only come inside when the door is unlocked. Which is so peculiar and frankly frustrating because everybody else can also come inside.

I've had this fat neighbour who invites himself into my apartment, used my shower and painting easel, ate my grilled cheese sandwiches and played my video games on a regular basis unless I lock my door. The best part of that is, we're not even friends!

Is it a bug or am I just plain silly for not doing it right or something? I thought it was supposed to be quite straightforward! You put a lock on your private abode and you give people you trust a key, so they can let themselves in.

Enlighten me... Please.

McFizzleShizzle

I think giving them a key just triggers random events when they decide to visit, I don't think it has anything to do with the actual door locks
The neighbours walking in and making themselves at home is annoying me too, especially since my sims are enemies with all their neighbours! They'll argue or fight out in the hallway then the neighbour will come in and play on the games console!

DeKay

The key allows your friend to come in at any time. Most other sims who don't have the key will only come by and stand by the lobby outside your door. But of course there are the annoying neighbors who get bored or hungry and would want to come in. It's not a bug. But you can always ask them to leave. Or try to put that private dwelling lot trait and see if the helps.