Do you have to like someone to love them?

So I was at work today, having an interesting conversation with a coworker. We began discussing our plans for the upcoming Easter holiday when the conversation shifted to family and yet again, as it often does, became a conversation of how we define things. Last week we had a conversation of how you define personality. But today we were talking about how you define love and like. I made a comment about how you can love people but not like them, he did not understand. I told him how I believe it's possible to love a person such as a friend or family member but not like them. He didn't agree. He believes that liking someone is a prerequisite to loving them.

I've always believed that liking someone is not a prerequisite for loving them if that person is a family member. But he sees it differently. According to him, the "love" I have for my family is simply social obligation to them. I wonder how many people see this the way I do, and how many share my coworker's view.