Praise be to Allah.
There is no doubt that breaking the fast in Ramadan with no legitimate excuse is a major sin and grave evil. If it is done because of an excuse such as travelling -- which means a journey of approximately 70 or 80 km, which is the distance that could be covered in one night on mounts and on foot, which is what is called travelling -- there is nothing wrong with breaking the fast in this case. But if one is at home or on the outskirts of the city, that is not called travelling and breaking the fast in this case is a major sin. The one who helps the person to break his fast shares with him in the sin, because Allah, may He be glorified, says (interpretation of the meaning):
“Help you one another in Al‑Birr and At‑Taqwa (virtue, righteousness and piety); but do not help one another in sin and transgression”
The one who helps a person who breaks the fast in Ramadan without an excuse, by offering him food or coffee or tea or any other food or drink is a sinner who is a partner in sin with the one who breaks the fast, but his fast is still valid and is not invalidated by his helping that person. But he is a sinner and he has to repent to Allah.
As you forced your daughter or your son's wife to make the food, you have to repent to Allah. You did wrong by telling her to make food for him. She did right by not obeying him, because there is no obedience to a created being if it involves disobedience towards the Creator. The Prophet (blessings and peace of Allah be upon him) said: “Obedience is only in that which is right and proper.” If her husband ordered her to bring him food during the day in Ramadan, without any excuse that would make it permissible for him to break the fast, such as sickness or travelling, she has no right to help him to do that which Allah has forbidden, even if he gets angry or divorces her, because obedience to Allah takes precedence over obedience to one's husband or father or ruler, because the Messenger (blessings and peace of Allah be upon him) said: “Obedience is only in that which is right and proper”; he also said: “There is no obedience to any created being if it involves disobedience towards Allah.”
This man is not regarded as a traveller because he stayed with them for a week and it seems that he had decided to stay for more than four days. This means that he was obliged to fast according to the correct scholarly view, which is the view of the majority of scholars. As they had decided to stay for more than four days with their in-laws, they should have fasted with them. If the stay is four days or less, they are not obliged to fast because they are travellers, but if they do fast, there is nothing wrong with that. But as they intended to stay with them for more than four days, what they should have done in this case is fast, so as to avoid an area of scholarly disagreement and so as to follow the view of the majority, because the basic principle is that one should fast in Ramadan, and there is some doubt as to whether it was permissible to break the fast. End quote.
Shaykh ‘Abd al-‘Azeez ibn Baaz (may Allah have mercy on him).