Is it permissible to eat at the house of a man who works as a hairdresser for women, and is his work unlawful (haram)?

If your relatives' work is unlawful and their earnings are unlawful, then they must abandon it and adopt another lawful profession. Allah provides a way out for the righteous and sustains them from where they do not expect. It is not permissible for relatives and friends to eat their food or drink from what they possess if all their income is derived from this unlawful work.