* He gets defensive. If you mention something positive about the other guy, he might get defensive and start to argue with you. This is because he feels threatened by the other guy and doesn't want you to think that he's better than him.
* He tries to isolate you. He might try to isolate you from your friends and family so that you're more dependent on him. This way, he can control who you talk to and what you do, and he can make sure that you don't have any other options.
* He gets angry or violent. In some cases, a jealous guy might become angry or violent. This is a sign that he's out of control and that he's capable of hurting you. If you're in a relationship with a jealous guy, it's important to get out of it as soon as possible. Jealousy is a destructive emotion that can lead to serious problems. If you're not sure if your guy is jealous, look for the signs. If you see any of these signs, it's important to talk to him about it and set some boundaries. If he's not willing to work on his jealousy, it's time to move on. You deserve to be with someone who makes you feel safe and loved, not someone who makes you feel jealous and insecure.