Why does my wife show others the text messages I sent her? Is it good or not? What is the general motivation?

There shouldn't be much motivation. Some of them are to let others know that they have such a considerate husband. Out of vanity, it doesn't matter It doesn't matter as long as it doesn't affect your life. If you don't like what she does, you should tell her what you think in time, so as not to affect you at this bad point in the future. Couples should be more understanding and tolerant before. Of course, the most important thing is communication. I wish you happiness.