Green Eyed Gremlins.
That is a fine line between envy and jealousy. Envy seems like a "wishing I had what you have" and jealousy seems like a "threatened by/insecure about what might be taken away from me" kind of feeling.
My best example of an envy/jealousy trigger was in the last triad we were in. I fell in love with her, but she did not return that love. She fell deeply in love with my husband instead, and I was pretty envious of him being the sole recipient of that love. When he returned those feelings, it brought up jealousy for me. It was a pretty deadly cocktail, and I found myself in a real emotional shitstorm there.
For me, they are both challenging to deconstruct, but I think the main thing is to not give into them. They are legitimate feelings, and bring up a lot of valid issues, but in the end they are just feelings and for me, that was a pretty important realization. Taking those emotions and deciding to allow them to be the trigger for positive steps to manage them can be very empowering - seeds of jealousy/envy can result in some pretty beautiful personal growth!