Relativism does not mean that moral claims become mere matters of passing fancy; it means that moral claims express preferences of particular minds (including speakers' and listeners'); understanding them requires understanding something about the minds of those who make them.

Understanding their content, understanding why the speaker considers them true, or understanding why they are true-for_speaker?

Consider: As an English-speaker, you might find it distasteful if your neighbor named her daughter "Porn". You might even think it was wrong, especially if you had concerns about how other English-speakers would react to a little girl named Porn. If you were a Thai-speaker living in a Thai language community, you probably wouldn't see a problem, because "Porn" means "Blessing" in Thai and is a common female name. Understanding why the English-speaker is squicked by the idea of a little girl named Porn, but the Thai-speaker is not, requires knowing something about English and Thai languages, as well as about cultural responses to different sorts of mental imagery involving children.

Is the more general principle "don't give your children embarrassing names" equally relative? How about "don't embarass people in general "? Or "don't do unpleasant things to people in general"?