My wife and I remarried. She hid the fact that I lent money to my ex-husband. I found out I sent a message to her ex-husband. Why does she want me to apologize to her ex-husband?

It is difficult for an honest official to break housework. What matters to you depends on why your wife lent money to her ex-husband. If the reason is justified, you can apologize to your wife's ex-husband and tell her that this kind of thing will happen in the future and discuss it with you. Don't borrow money secretly. If you borrow money for the wrong reason, you should be confident, there is no need to apologize, and be prepared for divorce.