Responses
I think he actually said it with a sarcastic tone "Not blood related, huh? " because earlier, when they first meet each other at the house.. The MC's mother told that MC and ML isn't blood related but then the result shows that they have blood relation.. Idk if there are some tricks behind it or what tho

It’s confusing
He say not blood related but the maids said biological and it seems that he was disgusted cause he was having relationship to his biological brother…. Which is which?