Hi,
How is your husband's allotting money to his mother affecting you? I suggest stay out of his relationship with his mother as this will be the sane st way to deal with it. She is his mother and I do not think that you should ruin your peace of mind and his as well by bringing this topic up. He knows what he is doing and by showing your displeasure or concern over him giving money to his mother is only going to spoil your relationship with your husband.
Magbasa pa