Jealousy is a waste of energy and shows that the person who is jealous is immature and insecure. If someone is deliberately making you feel jealous then don't sink to their level by doing the same thing and ignore them. If it is the opposite sex doing it to you then be stern with that person and tell them it's a childish game and you don't play games so either they are serious about you or you'll kick them to the curb.
