Is the money of the fiancé's father, who works as a night manager in a hotel, unlawful, and what are the resulting rulings regarding dealing with them and continuing the engagement?

If the suitor is righteous, the engagement should not be broken. It is permissible to accept gifts from his family and eat from their food, even if his father's money is mixed with both lawful and unlawful earnings. This is because the preponderant opinion is the permissibility of benefiting from mixed money, as long as the unlawful portion is not predominant.