Wife asking husband’s permission to fast when he has another wife
Question

                Is it obligatory for a wife to ask her husband’s permission to fast if that is on the other wife’s day?
Praise be to Allah.If the husband is 
    present with her then she should not fast without his permission, because he 
    may need her. But if he is with his other wife and it is the other wife’s 
    day, then it seems that it is o.k. for her to fast with or without his 
    permission.