Can a husband and her in-laws insist on a wife to eat the leftover from her husband’s plate?

A rebellious question; I agree. I live in Tamilnadu, India, that was once upon a time a great country with enviable culture and civilization. The related incident had happened on this Christmas Day. After the festival lunch, the husband had left over so many items in the plates. In the past the wife refused to eat it and the husband was pive about it. But this time the In-laws present there felt offended when the wife refused to eat leftovers and the husband too joined in the fray. They said that it is in the Indian tradition for a wife to eat such things and faulted her for it. But firmly she stood her ground in spite of the unpleasantness it created. While I complement her for her being firm against provocation I am eager to know your views about this obsolete and vomit-inducing practice. Why not the husbands practice eating the garbage item before insisting on wife to do the same and faithfully stand by Indian tradition? Snake Charmers’ land? I say ‘Yes’. You fume? Yes, you should!