I'll just add this:
The MC does owe friend cortesy to Erynn, a lot of cortesy, he has been stonewalling this girl for years and yet she still wants to reconnect, THAT'S FUCKING AMAZING!!!!
Given the information that we now know about the way he stonewalled her for the last few years, if Erynn reacted to the MC with complete indifference, i wouldn't blame her, not even a little bit.
This is an old friend trying very hard to reconnect, despite the MC being an asshole to her for years... and yet he "owes her nothing", seriously what kinda person thinks like that? One that is a terrible friend honestly.
"Ah she hangs out with Ethan..." i won't even bring the fact that she's being blackmailed, there's no need for it.
Erynn is well within her rights to hang out with whomever she wants... We don't get to decide who our friends hang out with.
If the MC thinks that Erynn should stop hanging out with Ethan, he needs to sit down and explain to her why, why he's a bad guy, the things he did...
Even then people might still disagree, they might see things differently, might think it's not a case for completely cutting the other guy off...
But at least after the talk he would have solid grounds to say "if that's your decision... i guess this is it for us".
This isn't even about Erynn, we don't have to go through any of that because Erynn hates him too, more than the MC.
This is just common sense of having friends, who have other friends, including someone you may think is a huuuuge douche...
Can you imagine if a character, any character, went "I want you to stop talking with Layla, i don't like her" and gave no further reasons?
The fun part is that Erynn isn't making any of these demands to the MC, she's just happy he's here.
The MC is the one that after 5 years comes around still pissed off and considering UNNACEPTABLE that Erynn is "friends" with a guy he hates.
In my opinion the Erynn relationship grows up very naturally, it's not dumped on the players by surprise.
At first she just wants to be friends again(and we have plenty of options for simply staying friends), she even fights and tries to deny the attraction she's feeling... until she can't fight it anymore and they start making out and eventually dating.
Sometimes i wonder if people actually play her route? Or just go "ahh she's annoying" in the first 5 minutes and never try again?
I don't think i have anything to add... just kudos