Jealousy Support Group
Jealousy typically refers to the thoughts, feelings, and behaviors that occur when a person believes a valued relationship is being threatened by a rival. This rival may or may not know that he or she is perceived as a threat. If you or a loved one may have an issue with jealousy, this community is a good place to start exploring the issue and get support. We're here for...
If it was before, let it slide and don't say anything; he is just trying to avoid upsetting you. By not getting upset about it you can prove to yourself that you don't have to get jealous, which will raise your self-esteem.
If it was after, you might want to think about just breaking up. You deserve better. I have hurt people by lying and cheating and if they hadn't left, I might not have ever learned anything. If you don't want to break up, you will need to confront him and make it clear that you won't be tolerating this type of behavior. You don't have to be mean about it, just let him know you don't want that kind of relationship.