1. One should not eat together on the same table cloth with ghair-mahram male relatives, Either all the spouses should eat together or men should eat separately and women separately.
2. Another important point which must be taken into consideration is that young childern are adopted and when they grow up and reach adolescence, the women of the house tend to say, “Ohl What Hijab is there from him? I have cleaned his nappies and took care of him since he was a baby? Understand this point well: The rules and regulations of Shariah pertaining odolescence are separate and the rules and regulations pertaining adulthood are totally exclusive. What does cleaning nappies have to do with anything? You cleaned your own child’s back-side and private parts when he was a baby, do you do the same thing when he grows up and becomes a man? Obviously not. This is because the ruling changes in adulthood. Now, If after adulthood the ruling changes for one’s own child, one’s own flesh and blood, then what do you think about that adopted child who is not even your own? Not adopting Shar’i Hijab from such people is a major sin.
Similarly, another disease which has become very widespread these days is to regard someone as one’s “brother” or “sister” when in actual fact he or she is not so. No one can simply become your lawful brother or sister by word of mouth.
(Source: https://www.ka.org.za/content/ghair-mahrams)