I had a lady from China stay for a week. I give guests the option of locking their door if they want. Some do, some don’t. But this lady would lock the door when eating breakfast, lock when getting fresh water, lock it if talking to me in the house, using her bathroom, even brushing her teeth and she locked herself in at night.
She was going to stay in a family home for 8 months as an English student, I did tell her that she probably won’t have a lock on her door, she nearly had a heart attack when she arrived to her host family and she had no lock