Bism Illah wa as salaamu alaykum wa Rahmat Allah Wa Barkatuh.
This is a sensitive subject, but it is the biggest and hardest aspect to deal with for many women in polygyny - marital intimacy. I know that many women feel that they never want their husbands to touch them again once he's been with another woman. They struggle with feelings of diminished confidence, jealousy, suspicion that he is lying when he says he still wants them, and disgust. It can be even harder because, with polygyny, it is not a secret; he has legitimately taken another wife and is living with her for part of the time.
I'm sure some of you may have wondered how I handled this and if I went through those feelings. Most certainly some of those negative thoughts went through my mind, but I knew they were from shaytaan. I also avoid my own slanted interpretations of things. After all, if I have no reason to think I am undesirable or less in some way, then why on earth should I think it?
Certain factors will always play a big part in how the woman feels and how she copes. Much depends on how the husband handles the situation. He must make her feel especially wanted and desired to compensate for the fact that he is also enjoying someone else. He must make it his responsibility to ensure the existing wife/wives are well taken care of in this area.
However, a different approach can be taken to the whole subject. Women don't get married to be left hanging and frustrated. It is the husband's duty to keep his wife/wives fulfilled, regardless of his obligations to, and desires for, another wife. If a wife is left feeling frustrated or ignored, it could be a huge source of fitna and resentment of his other marriage. It is essential to eliminate all aspects that will sabotage positive thinking and success in polygynous situations.
So, rather than think to yourself, 'I don't want him to touch me now he's been with someone else,' think instead, 'I'm getting some of my marital rights from him.' For every night that you think he is pleasing her, ensure he pleases you on your night/time, inshaa'Allah. I'm sure it must seem quite a tough approach as opposed to the hurt and confidence shaken one, but it can work very well bi idhn Illah ta'ala. Even if you imagine that your husband is having relations with his other wife on every one of her nights, exercising your marital rights on your nights gives you equal psychological footing.
As my husband so clearly stated on his blog, it doesn't go down well in polygyny for the man to be too tired or have a headache, LOL. From a female perspective, I think that most men think they are "too much man" for one woman and can always handle more, maashaa Allah. Just say to him, "Prove it." ;P