Poor guy's at his limit. It's obviously on him but I can't really blame him much, dude was under a lot of stress and Koto provided some much needed comfort.
I guess he wants to keep some memories of it, but he really should've waited for the pictures...
Honestly the only way Miya could've not hated him is if he ended up being some angel perfect dad, you can tell she was looking for any reason to hate him when she ignored the fact that her dad was with another lady at the shop. Miya completely ignored the other lady he was with, too.