Why girls discuss deep topics with a guy friend?

Last night I found myself in a conversation with a close girl friend. We liked each other a few months back, but we both decided to definitely stay friends. Last night though, the conversation worried me. We got on the conversation of love and marriage, and she asked what I thought about certain things. I told her thinking nothing, and she kept making comparative comments of agreement or disagreement on what I said. She would then add her own beliefs after what I said. She even told me jokingly not to judge her on certain things.