Can't understand why the need to be recognized by the father. He no longer pays MC as a tutor, he doesn't pay for the house they're in, they're working and supporting themselves, he don't own them and can't dictate how they spend their time... other than the school fees, they pretty much have nothing to do with him anymore.
They don't need to make a big deal with the father hiring that new tutor, they can just do what they did to their tutors before MC appeared - ignore him, and just continue to to be tutored by MC. It's not like he can force his way into their house... hell they can even kick the father out for trespassing...