I always hated that in sims games. I haven’t tried having family split into two households in S4 yet, but I have in S3 and it was relentless. My sims would go to their grandma’s house, and they would get yelled at for taking food out of the fridge, using the shower, and sleeping. It’s not like they walked into some stranger’s house.
Does the game track family relationships across households? If not, I suppose you could do those things in a good friend’s house.
I ran into trouble with the inappropriate thing when having a cooking club. When hosting a gathering at the active sim’s house, guests would do whatever they wanted, but when I went to another sims house during a gathering and if I dared to open their refrigerator... watch out! But the whole purpose of the club is to cook at eachother’s house.
I say all ‘inappropriate’ restrictions should go away when you reach a certain friendship level, such as good friends, and if actions are done through a club.