Sometimes you're on the 15th floor and someone gives you the name of a person of interest. They might not want to let you look around inside, but they could be much more willing to let you in just to use their phone. This could also let you sneakily get a look inside for vents and similar.
If your request is granted, the NPC tries to lead you from the phone. If you do not follow, the NPC waits for you for a moment, and if you are inside the home but still not following, or explicitly walk away, the NPC locates you, and asks for you to follow. After a period, if you do not follow, you are considered trespassing in orange and the NPC asks for you to leave. If you still refuse, your trespassing status updates to red.
-During this behavior, when you are found, the NPC will engage in dialog with you, forcing you to agree or disagree to follow, preventing people from exploiting the feature to get inside without a key or guest pass for any significant period of time. This is because the player will be interrupted by the dialog menu coming up, and if they disagree to follow, it could trigger a response immediately instead of waiting for a timer to decay.
-The NPC should also know which way the player went in their house, even if they didn't really see it. This means you could hide it you pull it off fast enough, otherwise you'll get found. AI seems a bit too clunky to have them go looking for you without help, considering how easy it should be to ask to use a phone and thus how easy it could be to exploit it for breaking in if the proper safeguards aren't in place.
-The following distance and time to wait should also be short enough that it's hard for the player to lose the NPC.
-While inside, you can operate doors, flick light switches, and use the phone and city directory. Doing anything else will cause the NPC to ask you to leave, or if it's a more serious or illegal action, respond appropriately.