When you discover your spouse is cheating, the most important thing to do is to be proactive. This means tracking their phone activities, social media posts, email and text messages, etc. This way, you can be sure that you have a clear picture of what happened. The next step is to try to talk with your spouse about the cheating. This can be difficult, but it's important that both of you are on the same page about what happened. Do not get into a fight or accusatory mode; this will only make the situation worse. Instead, try to remain calm and rational during the conversation.