Thinking about how both Tamlin and Lucien were so clearly willing to try and fix their friendship. Rhysand even acknowledges out loud that Lucien still has hope to reunite with Tamlin.
Sure, Lucien came back from Spring once with a black eye but then Tamlin invites him to the Spring Court for Solstice despite their fight. And Lucien just goes, no questions asked. Lucien then stays the night at the Spring Court and hunts breakfast for the two of them so they can eat together.
Clearly whatever happened as their relationship deteriorated, nothing was bad enough to break them apart for good. The friendship still matters to them, they still care about each other.
And then Rhysand inserts himself into the situation when it is not his business and tells Tamlin that he deserves to be alone forever because he's such a despicable guy and he'd be better off dead, actually. (Psychopath behaviour btw)
And Tamlin believes this and kicks Lucien out, complete with sending him all his belongings like a couple going through a divorce. Even then Lucien still doesn't say a bad word about him. Still defends him, is still on his side. The loyalty is still there. And he doesn't blame Tamlin but is aware that this is Rhysand's and Feyre's doing.
They were so willing to try and make up! Despite everything, they had hope and tried. And then Ryhsand ruins it. He just cannot risk them rekindling their friendship because that would mean less control over both of them.
