After finishing the second spoon of honey, Kagura Hikaru felt no more change than when he had taken the first spoon.
It didn't get better, nor did it get worse.
In other words, by the time he ate the first mouthful, he had already fallen victim to it, and eating any more would probably have the same effect, at most causing him to overeat.
His decision to finish the honey wasn't because he felt he needed to consume it all to carry out his undercover plan; he was mainly worried about his family members finding it and eating it without permission.
If they were affected too, it could turn into a complete disaster for the whole family.
However, as he raised the spoon to start eating, he suddenly realized something was off.
He originally had no reason to finish the honey, yet he inexplicably convinced himself with a seemingly logical but actually illogical reason: fear of his family secretly consuming it.