Annoyed at the duke

I mean, it's all great that shushu helped them to uncover the truth, and the duke punished that annoying teacher. But it's really off putting to see, that the duke didn't pay attention to his own child, until some other child mentioned it. It shouldn't be anybody's responsibility, but his own to realise and check up on his children. It's weird how he always gives shushu the pass, and treats his own children secondary to her. Where's the equality dude? He warmed up to her quick, but can't give a flying f*ck about his own children, strange