My problem with living together is based on religious beliefs, and honestly it is not just living together but sex outside of marriage. Sometimes you don’t know what is going on in a relationship(unless they discuss their sex life openly), but living together would imply that they are most likely having sex. Not my choice to make, but it is my choice to make rules for my house. I also will not tolerate bad language in my home, if it is a guest I might let it slide once but then I would have to ask them to refrain from such in my presence. I feel that it comes down to respect, just like the fact that no one ever brought alcohol into either of my grandparents houses(even though there were definitely some that drank) because they had enough respect for them to abide by their wishes.