The first wife’s approval is not a condition for marrying a second wife

 

My question is if you would help me to know the Hadith or the point of vieuw from the Islamic law on the follwing situation.


If a woman is married to a man and that this man is also married to an other woman without her, the last, knows about this marriage.


No need to say that this is a difficult and very exceptional situation but seems the best concerning the circumstances?

Praise
be to Allaah.  

The wife’s approval is not a condition for plural marriage,
and it is not obligatory for the husband to have the approval of his
first wife if he wants to marry a second wife. But it is good manners
and kind treatment to approach the issue in such a way as to reduce
the pain which women naturally feel in such cases, by smiling at her,
greeting her warmly, speaking nicely to her and spending money on her
according to his means, in order to gain her approval. Fataawa Islamiyyah,
3/204. 

If a husband takes a second wife, he has to treat his
wives equally as far as possible. If he does not treat them equally
then he is exposing himself to a stern warning, for it was narrated
from Abu Hurayrah that the Prophet

(peace and blessings of Allaah be upon him) said: “Whoever has two wives
and inclines more towards one of them than the other, will come on the
Day of Resurrection with half of his body leaning.” (narrated by al-Nisaa’i,
‘Ushrat al-Nisaa’, 3881; classed as saheeh by al-Albaani in Saheeh
Sunan al-Nasaa’i, no. 3682). 

When Allaah permitted us to marry more than one woman, He said (interpretation
of the meaning): 

“but if you fear that you shall not be able to deal justly
(with them), then only one or (slaves) that your right hands possess.
That is nearer to prevent you from doing injustice”[al-Nisaa’ 4:3] 

So Allaah commands that a man should restrict himself
to one wife, if he knows that he cannot be just. And Allaah is the source
of strength. 

See Fataawa Manaar al-Islam, 2/570.