Imagine a random encounter on the train. A stranger talks to you about Catherine. He speaks of her wonderful eyes, her sweet grumpiness in the morning, her bewitching glance, their small fights, and past holidays. You listen to him, wondering whether they are married. During the conversation, however, it turns out that he was not talking about his wife, but about his college friend. I guess you would feel embarrassed by his description. Generally, we have a good sense of the distinction between several modes of love and when the distinctions become blurred, we feel irritated.