My ex-husband and I will meet at a relative's wedding. How should I conduct myself?

Be polite and brief: give salam if appropriate, keep your distance, and focus your attention on the hosts and the children. The occasion belongs to the bride and groom, not a place to settle old business. Plan ahead: who sits with whom, and when you arrive and leave. If the children are coming, talk it through before the event so they are not caught between the two of you. Avoid long conversations or raking up old matters in front of relatives. If your heart is too heavy, there is nothing wrong with attending only briefly, or sending a gift and prayers from afar. The Prophet ﷺ said: “A good word is charity” (Sahih al-Bukhari 2989). See etiquette with an ex-spouse.