As Jay-Z said, "Jealousy is a female trait". Men don't get jealous, they get envious. Envious of what others have that they don't have.
I've been envious before, and then thought, "that was stupid", because the energy that goes into that could energy put into more productive things. Plus, people feed off of that energy, so why give the party that your envious of, more power? Give them credit and a pat on the back, and you feel better.