When you catch your girlfriend cheating, it's important to remember that this isn't an attack on her character. It's something she needs to deal with and learn from but also you can check a few of their recent reports there for physical sign that your girlfriend is cheating or not. Anyway, The first step is to set boundaries. You can't simply say, "You're not allowed to have any more contact with him!" because that would be a relationship-killer, and you don't want one of those in your life anyway. Instead, you need to establish some rules for yourself so that the two of you can move past this situation together.