How do I deal with cultural differences, my boyfriend is from India I'm from Ecuador and we get along very well. He invited a friend of his in town, who is not even close to him, and she's staying in my room (which I agreed to because I thought she would be respectful). I don't like the girl and I told her out of politeness that she can use what she wanted. In my culture when you say that to a guest you don't really mean it and guests don't use your things.
The girl has used my things, and kept things in the drawers which I did not tell her she could use, my room is a mess and I told her to please clean it after she leaves. I'm stressed because she's staying in my place and not taking care of my things because in her Indian culture if you have a guest home he/she can literally make themselves at home. Any advice, I don't know what to tell to my boyfriend