“Envy: a feeling of discontented or resentful longing aroused by someone else’s possessions, qualities, or luck.”
One of the 7 Deadly Sins and an emotion even modern philosophers consider to be beyond the pale. So let it go. Really, for your own peace of mind and good karma. Let. It. Go.
Maybe envy is not the sin you should let go? The New York Public Library and the Oxford University Press published a series of books on the seven deadly sins. See which ones you need to avoid.
Are you scared of being too envious? Sponge Bob can teach you a little something.