So to sum it up:
Dad still doesn't know what to do or how he feels and could never come up with a lasting assertive response,
Kii-chan may well never actually had feelings for the Dad and was only using him as her escapade,
Mii-chan still couldn't move on from her mom's death and would rage against her dad if he ever did,
And Kii-chan's mom is parental abuse itself personified