When is thinking in terms of forever dangerous?

1. When one party isn’t being honest.
2. Forever is not something one can promise. With all the best intentions, think of the bride or groom who died on their honeymoon. It happens.
3. When one or both partners change drastically and they are no longer compatible.

Not sure what you are asking. But I reckon if the partner has lashed out physically. No matter what they say afterwards, they are forever dangerous.

Relationship wise, it is dangerous because it, of course, leads to the two parties taking each other for granted. I guess that goes for any resource, really. Oil, coal, our good health, .... thinking it will last forever, simply, is dangerous. Thinking that there is a never ending well of forgiveness, energy, tolerance, support, subsidies, desire, that is simply not true, for anything or anybody. Entropy happens. If you don’t recognise that and do what you can to maintain your resouce, it will run out, end or simply come at far to high a cost, eventually.

When the person is very young, a teenager and still has things to complete to start on their path into adulthood. Education, learning about oneself, pursuing interests, etc.

I also think @cazzie gave a great answer.

When you are human. You need to be humble enough to recognize that we cannot see the future, only give it our best guess and act with good intentions. We proceed and correct course as we go. Being too rigid isn’t good. Being able to admit your mistakes will serve you well.

Thinking in terms of forever is dangerous when one thinks the present will be static and that things won’t change. Things always change, so thinking “forever” in terms of how things will change is actually good and a way to shape one’s own future.

And in a relationship, it’s how a couple can grow together.

One thing that never changes is things always change. I’ve told this old Vietnamese proverb many times, but it’s so true. “The same man can never go to the same river and put his toe into the water. The man is different and the river is different”. Change happens.

Your insurance agent/company. I’ve learned there’s always a better rate if you look for it.

When you’re depressed.

That your children will not grow up and move far away.

“Forever” does not apply to ANYTHING!
Especially relationships.
Even if a relationship lasts until “death do us part.”
Part we will.

The nature of life itself is transient and everything is of an impermanent nature.
No-thing lasts forever, good, bad or indifferent.

Hold on loosely. :-)

I don’t know if I would use the word ‘dangerous’, but no one knows what’s gonna happen tomorrow – therefore thinking in terms of forever is always unsure.

None of are guaranteed a tomorrow. We must daily, do what we know is right especially as it relates to people in our lives about whom we truly care. We ignore such advice at our peril.

When your ‘shute fails to open and the ground is still several hundred feet below you.