The reason that Green could guess as to why they forbade Green to meet Katsuki was that Katsuki could cause trouble for Green.
At first, Green was able to contain all his curiosity and curiosity, but because Eijiro had not returned to the mansion for weeks made Green's worries even more intense. Green couldn't let this drag on any longer.
'I have to get out of here and leave this place to meet Katsuki. I have to make sure that Eijiro doesn't do anything bad to Katsuki. I also don't want Eijiro to have an affair and force Katsuki to be his lover.'
Green is now in his own thoughts, he is indifferent to his own circumstances. Green had convinced himself to keep figuring out what Eijiro was doing until he hadn't been home for weeks.
Now what he had to do first was convince the servants that he would not go outside the mansion for reasons that could harm him.
