My wife and I rent a house, and the landlord lives next door. He often chats and talks to my wife, and sometimes he is courteous, and my wife doesn't refuse.

The landlord is dishonest and wants your wife's good things. Your wife is pretending to be confused because she understands. She is an adult and it is just a look. I think you still need to beat your wife for a while, warn your landlord, and then move out of your landlord's house immediately and rent a house elsewhere. This is very important, it is related to your own dignity and cannot be tolerated.