A question recently arose in a Facebook group with both frum and non frum members as to whether a woman who is outwardly frum but inwardly not keep the halachos is required to inform other members of the frum community before preparing food for them. The husband is aware of his wife’s current religious non-observance.
Is one who keeps kosher allowed to eat in this home (from this home)?
Is the husband or wife obligated to tell anyone eating from this home that the wife is not observant?
Is the halacha different if it is the husband who is not observant as opposed to the wife?
This is a very painful question, and it unfortunately can cause tremendous difficulty to the person’s family members. Whenever someone is in such an unfortunate situation, they will need the guidance of a Rov, and he should be asked this question. I cn make a comment about it, but only on a totally theoretical level. Essentially a person that is not observant can not be trusted when they say that something is kosher etc., however R’ Moshe writes that in an instance that the person trusts the other one i.e. the husband trusts his wife on a very high level, that she would not give him trief to eat, then he can rely on what she says. However others that are not as close to the person and would not trust them to this degree, would have a problem eating there. Again I am only saying this as a thoeretical point, not as a halachic psak.
Igros Moshe Y:D 2-43