Bism Illah wa as salaamu alaykum wa Rahmat Allah waBarakatuh.
A sister sent this question to our Madinah Naseeha e-mail address and both my husband and I have decided to answer the question jointly and post it on both of our blogs. The question is, if a husband makes clear that he is seeking another wife and plans to practise polygyny, how honest should the wife be if she isn't happy about that? Should she stop being honest to keep the peace?
Honesty is extremely important, and the difference between people understanding you and your actions correctly or not, lies in how honest you have been with them about who you are and how you feel. That said, it is important not to harp on an issue
There is a big difference between accepting the prospect/reality of polygyny in your life and liking it. There is also a big difference between disliking it, feeling hurt by it, and fearing it and going against Allah's commands and your duties as a wife to become a source of rejection and fitna in it. This is another test, sent by Allah, to be dealt with in the best of manners.
Here is a possible response to a husband's question: "I don't like the prospect of polygyny in my life. If you'd like to know the reasons, I will explain more. However, I am a servant of Allah and plan to act with emaan and taqwa throughout this test and seek Allah's help and guidance." This opens the door for him to choose whether he wants to discuss it further and really hear your concerns or not and makes clear that your intentions are good, but you aren't at peace with the prospect of him taking another wife.
Another possible answer is: "I can't talk about it." This gives a clear message to the husband that you are not in a stage of her life where polygyny is easy for you to accept. Your feminine nature is in opposition to your spiritual nature. This is something that is not wrong, but part of the female psyche. We cannot fault a woman for not doing backflips at the prospect of having to share her husband, time, etc. If he is a thinking man, he will realize that taking another wife it is not the wisest thing to do at that time. Although it may be permissible, it is not wise at all.
If approaching him and asking him questions won't cause discord, ask him why he wants to practice polygyny. However please note, you must be prepared for the answers. It is important for both husbands and wives not to ask questions that they may not like the answer to, or cannot handle the truth about.
If he says that he wants to practice polygyny because it is Sunnah, kindly ask why he has chosen this Sunnah over the other Sunnahs. You may remind him that the Prophet, salla Allahu alayhi wa sallam, practiced monogamy for most of his married life, and didn't practice it until after Khadijah (radhi Allahu anhaa) died. That is also a strong Sunnah. All of his marriages set a precedent for the Ummah, were divinely inspired, or were benefiting and strengthening the Ummah through key affiliations. You may ask how your husband's prospective marriage will benefit the "little ummah," your marriage.
Lastly, the most important thing is to make sure that the dialogue is peaceful and that family life stays harmonious. If any of the above advice would cause any type of problem, throw it away - don't take it. However, if you believe it will benefit, please by all means, use it.