In my experience, I think there's must ado about fidelity and infidelity. I think sometimes true emotional relationships can go beyond those.
To wrap up the idea of 'Parade's End' in a sentence or two, I would say it's a love story in which we see a man with two women, and we know what's attractive about them. And we know why and what they feel about him.
I know for me the subject of how to be in a relationship is precious and complicated and challenging.
Secondly, love and relationships are complicated. No one could ever get it right in a four-line sentence.
The counter-argument would be, so what if my sexual relationships are superficial, one can still have satisfying and rewarding relationships with friends, or parents, or siblings, or whatever.
So many of my favorite stories, in any medium, are about friendship. Those relationships are so often just as emotional and complex as any romantic or family dynamics, and yet there's a dearth of resonant, grounded films about platonic bonds in American films.
Relationships with people in general, in no matter what capacity, are something that's very emotional. They mean a lot to you. I think having eyes on that in a critical way can be really tough.
If pity is akin to love, gratitude is akin to the other thing.
We were discussing civilization and the fact that young men among the Greeks at that time were idiots and uneducated, so the men had emotional and friendly relationships with members of their own sex.