I said I'd elaborate on my thoughts on Lily's and the Alicein brothers' dynamics and I had a really long week so I'm relaxing by dumping my thoughts here once again. This might or might not make any sense, idk. Also I includes spoilers for the recent chapters.
So starting off chronologically, you know that Lily was supposed to form a contract with Mikuni.
I think this interaction is incredibly interesting, because it's Mikuni pointing out that Lily doesn't seem happy about him becoming his Eve. Like, it makes sense with their characters, Mikuni is observant and intelligent, and Lily is... really not the kind of person to outright say what he feels on that matter, especially given that his hands are tied by his promise.
I also feel like this panel is defining their later interactions though, especially in the recent chapters.
Lily is very much ready to put his own feelings aside and team up with Mikuni (and Mikuni is fully aware of it). There's some truth in every lie, and Lily was bound to end up with Mikuni from the start. He is ready to become his Servamp (which we'll use as an allegory for, well, the stuff going on with him right now) essentially for his promise (Misono).
And that is the difference between his connection to Misono and Mikuni.
Misono means a lot to Lily. If he has to lie to him and betray him to protect him, he will do so no questions asked, and no matter what Misono would want in the situation.
And that's what's drawing him away from Misono, but also bringing him closer to Mikuni.
What's the central similarity between these two characters? They're ready to set the world and themselves on fire to protect Misono. And, essentially, they both end up hurting him in the process, whether it's because the less painful option is still painful (Mikuni) or because he's not acknowledging what Misono himself wants (Lily).
If you like, lust pair's contract is built on an illusion, literally. But either way, Lily lied to him, which is... not ideal, considering that breaking the trust between Servamp and Eve can and, in that case, did end very badly for both of them. You know the concept of ending up hurting someone because you love them too much? That's Lily with Misono, 100%.
That's not really new information, but it makes things really interesting if we look at his dynamic with Mikuni now, or him teaming up with him at least.
He was supposed to form a contract with Mikuni but didn't, and that's the reason why he'll always be closer to Mikuni than to Misono. (Unless he does come to realize what Misono was trying to tell him at the end of lust arc.)
And, sure, you can say that this has nothing to do with Lily himself rather than how he feels towards either of the Alicein brothers and that their story wouldn't change if he had formed a contract with Mikuni instead of Misono, but both from an in-universe and outside standpoint, this doesn't make sense.
There isn't a single pair of characters in Servamp you could swap in the narrative without the storyline falling apart, and this is especially true with Servamps and Eves. The whole manga is a network of delicate dynamics that work this way and no other.
But also in-universe, it's just who Lily is. Whether he's his Eve or not, he loves Misono, and that'll always be what will make him unable to let him build the sort of connection he has with Mikuni.
Remember what Gear said about the characters of the last three Servamps? They may be more human, but in a self-destructive way.
Lawless, whose families killed and rejected him.
Ildio, whose freedom doesn't let him connect with anyone.
And Lily, whose love burns anyone that gets too close.
