Honestly and sensitively. This is likely going to be a discussion this child remembers for the rest of his/her life, a parent in this position will need to choose his/her words carefully.
I also suggest that in addition to expressing sympathy and providing needed support, a parent should (when the time is right) help that child (and his/her spouse too, if they have that kind of relationship as in-laws) explore whether everything that can and should be done to try to save a salvageable marriage (if salvageable) has been done or is in the process of being done.
Disposable culture does not apply to marriage. When spouses simply don’t get along (as opposed to one or both posing a serious threat of physical or pathological emotional harm), the temptation to treat a marriage/spouse as disposable usually just ends up kicking the can down the road.
A miserable (or near-miserable) marriage is hard to bear, but giving up on marriage is like amputating an injured limb. Amputation will “solve” that problem but needlessly cause others.
Saving a marriage does take work and does take time. In many cases, things get worse in the natural process of things getting better. But it is worth the effort. Even if the only thing a couple learns in that process is that they really are toxic for one another, better to be sure of it before divorcing than divorcing hastily or cravenly or selfishly and then spending the rest of your life wondering “what might have been” and/or “Oh, no, what have I done!?”
Utah Family Law, LC | divorceutah.com | 801-466-9277