Can Cultural Relativism help you in your dating relationship?

Cultural Relativism is the ethical belief that we should determine what behaviors are moral based on what our culture determines is moral. In other words what we "ought" to do and "ought not" to do are determined by the specific cultural group we live amongst. It seems that more and more Christians are being taught the problems and weaknesses of relativism. Most likely we identify the belief by the popular phrase, "That is true for you, but not for me."

Perhaps though you have found yourself in a conversation with someone who espouses Cultural Relativism and were at a lack for words to help them see the weaknesses of it. Even though we as Christians can identify ethical relativism when we spot it, we still may feel like we don't have an easy way to point out the weakness of this system in a conversation. Cultural Relativism is full of weaknesses, but I thought I would give one that can easily be used in conversation and provide an illustration as well.

1) The Weakness - Cultural Relativism can only describe moral behavior; it cannot prescribe moral behavior. Relativism can only tell us what is going on in any certain culture; much like an anthropologist would. It fails to be able to prescribe what we "ought" and "ought not" to do. This is a huge failure, because it means that ultimately I cannot make a moral decision because I have no standard that I "ought" to do.
2) The Illustration - Imagine an American man who travels to Kenya and meets a Japanese lady. They become romantically involved, and someone suggests that they move in together. Assuming the man and the woman are Cultural Relativists, how do they decide whether this is ethical? Do they use the man's North American model for dating? Do they use the woman's Asian model for dating? Or do they use the African model where they are living? All the Cultural Relativist can do is to describe the different beliefs that each of the three perspectives would have. In no way can it actually cut through the culture and say what "ought" to be done. In other words, epic fail.

Normally for a person to change their mind, they need to see some problem with the view they are holding. This is a fairly non-confrontational way to help Cultural Relativists see the non-sequitur nature of their ethical system. Hopefully, it can lead to a chance to share the Christian worldview, specifically the Gospel.