[Ignis doesn't seem to mind that Noct has no interest in eating the food. He just made it so he could feel in control of something, even if that something was the creation of a dessert. It's also his way to express that he was angry at the situation and his lack of ability to fix it, rather than anything else]

It would have been worse if he hadn't. If for one moment they suspected he knew of their betrayal... No, your father understood it was better they meet him on his own terms.