What does it mean for a man to say to a woman that he has a certain place for her in his heart?

There are two possibilities. One is that this man already has a family, or a girlfriend, or someone he likes, but he has some feelings for this woman. There are not many honest people like this in this society now, so this possibility is slightly lower. And his family, parents, friends and so on. I guess he wants to tell her that he is living a realistic life and she is the only one.