[Menage_a_Trois]

The jealousy/insecurity may come from the fact that relationships with secondaries are not on the same footing as primary ones. They are more like "dating", while the primary is a marriage or long term relationship. Not sure about the relationship you have with your secondary, but most secondary relationships aren't exclusive. So could the insecurity be about them finding someone else? I think I'd talk to my secondary about this and you might find that they are feeling the same way. Good communication could go along way to putting your mind at ease.

T, A, and P