Hold, please.

This whole time they're just trying to bring each other back into equilibrium and yet they can't actually just TALK about the true core of what their issue is.

Think about it: Buck is triggered by Eddie's desperate words said to the renter couple that imply that Eddie does not value Buck as much as Buck values him.

Buck then does and says a series of things that he believes will hurt Eddie and will make him feel what Buck feels. Obviously, their conversations are extremely revealing of how Buck feels: Like he's being abandoned, like he's not worth staying for OR coming back for, like Eddie doesn't need him and like he doesn't matter to Eddie.

He gets a dog as a replacement for Eddie. Buck knows how shitty it feels to perceive that you're being replaced. Take a look at his reaction to Eddie in 2x01. Then he says "don't want him to think I'm an abandoner" and "he knows how to stay." all of which poke at something Eddie is very sensitive about. He felt endless guilt over leaving Shannon and Chris for the military, and even more, feels shame over "pushing people to leave him" due to his own actions or inactions, like Shannon and now Chris.

Buck doesn't really believe all of these things, he just wants Eddie to feel the pain that he is feeling.

And Eddie is pissed, because how does Buck not see that Eddie HAS ALREADY BEEN in just as much pain about leaving? He just cannot show it as plainly as Buck can. Now he's extra hurt not just because Buck's bringing up some of his deepest insecurities, but because he refuses to talk to Eddie directly about it, and he hasn't since the second Eddie brought up moving. Neither of them is thinking rationally here. Both are spiraling out, desperately trying to think of something that will get the other to just UNDERSTAND.

And so Eddie pulls out a weapon that he knows will hurt Buck. "Everything really is all about you!" Eddie knows this is exactly what Buck is sensitive about. And although Buck doesn't mean to do it, by bottling up his true feelings, "it's what he turns it into every time". "You acted out like you always do" when in reality, Eddie just wants Buck to be mad at him and to TALK TO HIM. The truth is Eddie is mad, he's pissed off, and that hides the soft underbelly of how painful it is to be separating himself from Buck and LA.

But the second Buck finally lets go and tells Eddie the truth of what he's feeling, that he's not handling Eddie leaving well, the entire conversation changes. Eddie admits he doesn't want to leave. He doesn't like this situation any more than Buck does, and it's killing him that he feels he has to choose between Buck and his son because everyone knows that the choice will always be Christopher. It's easier to pretend everything is fine. It's easier to be angry.

And Buck realizes this before Eddie even has to say it to him directly.

So, instead of trying to hurt Eddie more to force an "I'm sorry, Buck, I do care about you!" out of him, Buck lets go of his insecurity and makes an ultimate act of sacrificial love. He manages to self-regulate his own emotions for once, and decides that he'd rather pour his love into Eddie and remind him just how loved he truly is by Buck than try to pull Eddie down into deeper despair. So Buck destroys a large chunk of Eddie's worries and anxieties all in one fell swoop, and the relief is so palpable for Eddie that he is fighting tears. Eddie knows how much Buck loves him, and Buck can feel that in return.

Eddie's anger and desperation in their final fight scene finally prove to Buck just how badly this is affecting Eddie. And reminds both of them that the way they love each other isn't conditional, nor is it rooted to being in the same physical location. Buck is happy if Eddie is happy, even if that means they can't be together.

"Um, do you care for him? You're romantically inclined toward this person."

“If she’s got the temperament for it, she should try her luck inland,” they advise. “No point her starting a temple here if she’d find her people elsewhere, with a little searching.”

At first, your parents are reluctant to send you away. Though you’re well-behaved and diligent in your chores, you’re a sickly child with no God to worship. And besides, you’ve always been the dreamy type–inclined to lose track of time watching the path of rain droplets chasing down the window, or the fronds of an anemone as it sways in a rock pool.

Instead, they send you to the temple of the Storm to learn all you’ll need for your own God. You are happy there, for a time: making up beds and serving food to the castaways who pass through, keeping vigil at the lighthouse, burning incense and praying with the loyal widows and orphans of the drowned.

One such widow, an old, old lady, touches the mark on your forehead. “I recognise those letters. We wrote this way in the town where I grew up, way off past the mountains.”

Your heartbeat quickens. “What does it say!?”

She squints, eyes engulfed by wrinkles and hidden behind smudged glass. “A… Ar… Oh, I can’t remember how to speak it. I left before I learnt my letters properly. There was a war, you know. But I remember,” she says, mistily, “the most beautiful pink and white flowers used to grow, on the borders of the wheat fields…”

You try to ask more questions, but remembering the war distresses her, and so you speak of other things. When she’s drifted off to sleep, you get to your feet, go home and tell your parents: you are leaving in search of your God.