There are two main ways to stop your Sim from getting the annoying “This is inappropriate” notification when visiting another household:
Get the Always Welcome trait.
Have a Sim from that household give your Sim a Residence Key.
If your Sim enters another household’s home uninvited and starts using their furniture, appliances, or other objects, the residents may scold them for inappropriate behavior.
If your Sim continues, they can eventually be kicked out.
The Always Welcome trait solves this problem by allowing your Sim to feel at home when visiting other Sims.
The residents won’t mind your Sim dropping by unexpectedly or using their household objects.
This can be particularly useful for challenges such as Rags to Riches, where your Sim may need to rely on other households’ facilities while they’re starting out.
Another option is to have a Sim living in the household give your Sim a Residence Key. Once your Sim has a key, they can visit that household without being treated like an uninvited guest.
This can be especially useful for family members who have moved out.
For example, a young adult who leaves their family home may still get the “This is inappropriate” notification when visiting their relatives and staying for a while.
Children can run into the same problem when visiting their grandparents. Using the fridge or taking a bath can sometimes result in the grandparents telling them their behavior is inappropriate.
If your Sim keeps getting kicked out of a relative’s home even though you want them to stay, you can use a cheat to give them the Always Welcome trait.
Open the cheat console by pressing Ctrl + Shift + C on PC.
Enter testingcheats true and press Enter.
Enter traits.equip_trait AlwaysWelcome and press Enter.
The Always Welcome trait will be added to the currently selected Sim.
The trait normally costs 500 Satisfaction Points in the Rewards Store, so the cheat lets you skip earning those points.