Jealousy always has more to do with you and your unrealistic fears, such as your fear of loss, abandonment, being alone and being rejected/left behind for someone else. Jealousy stems from feelings of internal inferiority, from a lack of love for yourself first, which leaves you incapable of wanting only the best for others, and in the end loving others. When you have the love for yourself, you can recognize that jealousy does not have to do with being realistic about the stability of your relationship, the bond, and trust you have with your partner. It does not lend to wanting the best for your partner. If however, there is something else going on, and your fears are actually based in reality (be honest with yourself, and remember you can get professional help too, it always helps to talk about these things) then before you make any sudden moves make sure you recognize the true nature of your emotions.
This is an excerpt from her book, Marriage, Money and Porn, available on Amazon.