You unlock some interactions apparently based on how you progress with characters. Try raising different traits higher so you can get better responses or reactions. Try shopping for items to get a new story option open. Sometimes its simply that you haven't gone far enough through the characters storyline as well. Make sure to click on other characters aside from the hotel residents as well as some have some very interesting material attached to them as well. Hope to see future expansions of some of them. Hint traits such as exhibitionism should be pursued to the full potential for the best results. Don't just do the one activity and stop. Max that out for better future results. It pays off nicely. Especially with Lin.