No matter how old you are, you have probably had a friendship where jealousy is alive and well. If this is something you are dealing with right now, my heart goes out to you because this can be an incredibly frustrating and confusing situation. This essay will focus on the situations in which a friend of yours is jealous or competitive with you, and you are the target of their negative emotionality.
A little jealousy is probably normal. I remember a Training Director of mine at a major hospital, Dr. Alan Hilfer, had a theory that people's inherent tendency is to feel bad for themselves when they hear something good happened to someone else. In other words, people are always keeping score. At that time, I thought this was a little extreme, but I have come to believe that this may be more a natural function of human nature than we would like to believe.
This may be why a little jealousy is normal. We all want the best of everything, and we want good things to happen to us. Sometimes we can get so caught up in our own thoughts and feelings, our own wishes and fantasies, that we stop thinking about others around us.
Friends who become overly jealous with you are taking inadequate feelings they feel about themselves, and getting angry and resentful with you as a defense mechanism. When these friends see you happy and feeling confident, it actually makes them feel more inadequate and more bitter.
If you have read previous essays of mine, you can probably imagine that my advice is to confront the situation with your friend. Remember that attacking someone verbally goes nowhere, so it is always safer to begin by expressing how you feel. It can help to ask them to put themselves in your shoes. "How would you feel if I said this or did this to you when you were happy?"
Think about the way you say something, not just the content of what you say. Wear a kind, understanding look on your face, and talk in a slow and gentle voice. You catch a lot more flies with honey. Using these skills is much more likely to help you because people are more likely to listen and hear you if you come across as an ally.
Finally, another skill you can pull out is to talk with them about what to do if your friend says or does something in the future that feels like a jealous, competitive jab. Ask your friend, "If it happens again, how would you like me to let you know?" This gives your friend a sense of control, and says that this is a collaborative effort on both of your parts to communicate better and treat each other more respectfully. You will damage your friendship if you scold your friend or talk in a patronizing voice.
These skills should make this kind of situation easier to navigate in the future.