I sorta agree, but at this point I don't think he knows what she saw, so going out like "hey, sorry, I was making out with your best friend, who I had a relationship with until she ghosted me" it's not what anyone would do, but yeah, it's damage control for a situation he partially provoked. Of course he should have told her about his affair and make things clear beforehand, but it is what it is at this point, he kept her in the dark and now it came to bite him in the ass like an idiot.
I honestly don't remember if Yuu even knows that Ayami is Hikari's best friend, or that they know each other. And yeah, that would be unrealistic, but he shouldn't be lying and telling her to cheer up - even more than being morally wrong, the greater offense in my mind is just how
superficial it is. Hikari's reaction to the perceived offense, as far as he can tell, is disproportionate: He should be more curious about this, rather than just trying to smooth things over, even if he has other shit going on. It's such a cruel indirect insult to her. Totally what you'd expect from a teen, but I hate to see it.
I know I'm also very much not these kids, but depending on what went down in that classroom, I as Yuu would almost certainly just go sit against the wall by where she's standing, apologize for disappearing without trying to make excuses, and say something to the effect of "Hoo-boy, I have just had an
afternoon. Kinda messed up by it and definitely not ready to talk about it, so please be patient with me, and I'm sorry for having to ask that of you. But. How are you doing right now?" I know, if they always tried to do the right thing it would be a more difficult story. But it's never impossible for him start lowering her down from that pedestal and actually telling her the truth and emotionally engaging with his (best? only?) childhood friend.
If he has no other supports in his life than Hikari, going through the dating Yami thing and coming out the other side seems so bleak and lonely.
I'm not sure he even has to feel guilty about it. For all we know, he might not even be aware that Hikari likes him, so from his perspective that kiss wouldn't hurt her. And he's not telling her about Yami just because it's extremely awkward to tell your previous crush about your new relationships. And even if he is aware, the kiss we saw was initiated by Yami, so he is technically not to blame.
To be clear, he shouldn't feel guilty about being in a relationship with Yami (shame, maybe, lol, but guilt, no.) Nor should he feel guilty about kissing her, unless he's doing the pretend-dense-protag shit of knowing Hikari likes him and not wanting that door to close while he gets it on with other chicks (in which case, I hope he enjoys his future as a knife block.) He should feel guilty about not seeing Hikari's messages and hurting her, unless it's only been like 45 minutes since the shift ended and he finally borrowed a phone charger and that's why he just checked the messages and found her new spot. And about trying to deceive her no matter what.
Is it awkward to tell your previous crush about a current relationship, if they're a friend and you're over that crush? Maybe I'm weird, but to me that's more liberating than awkward. Deffo max awks if he still likes her and wants to keep that option on the table, or if he thinks she'll think less of him for being/having been with someone like Yami, but both of those motives make him pretty crappy in my book.
Also, if it's not legal in 26 states for a crying girl to shoot a man dead who tries to use the word "technically" in conversation with her, it
should be. /s
Even if he's right. No, especially if he's right.