Is this emotionally abusive?

One of my parents, I won't name genders or roles for the sake of ambiguity, has been borderline hysteric all week. They are now on the phone with the other one (who is away on business) and is threatening divorce, hating Thanksgiving (a yearly thing), and has not been happy, despite a rather worry free life. They have a good job, have been saving up, and have in the last few years, been a miserable little s*** at holidays. We respected the vegetarian thing, worked around the snobbery of not wanting to travel on holidays, but now they are changing all the rules again. I've tried to stay close by, but lets face it, it's getting harder to stay close to someone who acts like this and threatens to leave when the tiniest things go wrong. This morning it was a late appointment with a weekend lawn person for aeration that set it off. Wreaked the mood for the whole day.

So what do you think? I've tried talking, but it only seems to boil down to bs. Things most people would be more than happy to have at all. A good, full time job with relative necessity (and no replacement always around the corner), a wealthy spouse who earns more but doesn't spend it, and all the children working full time jobs in their field. Not to mention a paid off mortgage, cars, and living in a nice neighborhood with no health concerns looming.

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