There's a couple of sayings:
Fake it until you make it and
Act as if
Jealousy can be surpressed, worked around and one can "act as if" everything is ok, until it IS ok.
You cannot be happy, and acting mad. Conversely, you cannot be angry while 'acting' happy.
Try it. Next time you're in a fucking miserable mood, having a seriously pissy day... Jump up, throw your hands in the air and yell "TA DA!!!" do it several times... and see if you're still miserable when giving it your all. You CAN behave in such a way that will change your emotions.
Emotions aren't nouns, they're verbs. Love is an ACTION. Jealousy is an ACTION. They're both real and valid and powerful, but they have to be given fuel - you have to ACT with love and ACT with jealousy for them to perpetuate.
Of course this is all fairly logical and when you're in the grips of a powerful emotion - its *almost* impossible to be logical. But there's always a moment of clarity when you have it in you to make that choice to act one way or another - whether or not you feel it.
So from one viewpoint - its a logical thing:
If I am being asked to act and feel a certain way - then why can't you?