Whether it is wrong for Christian men or women to wear a thong is subjective and depends on individual interpretation of biblical teachings and cultural context. There is no explicit prohibition against thongs in the Bible.
Some Christians may believe that wearing a thong is immodest or sexually provocative, which they see as conflicting with biblical teachings on modesty and purity (1 Timothy 2:9, Matthew 5:28). Others may feel that wearing a thong is a matter of personal choice and does not violate any biblical principles.
Cultural norms also play a role in how people perceive the appropriateness of wearing a thong. In some cultures, thongs are considered acceptable swimwear or undergarment, while in others they are seen as inappropriate for public wear.
Ultimately, whether a Christian man or woman chooses to wear a thong is a matter of personal conviction and discernment. They should consider their own conscience, biblical teachings, and cultural context when making their decision.