The following Hadith quite cleary suggests that the permission of women should be taken and does not say marriage, as some use it as marriage. Why then is it suggested that husbands do not have to ask his wife's permission? Aisha reported that Allah's Messenger said: "Take the women's permission in regard to their private parts ." (recorded by Ahmed and Nasa'i).

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.  

The Hadeeth that the questioner stated is correct.  This Hadeeth is reported by Al-Bukhari and others that 'Aaishah said: "I said: O Messenger of Allaah, should the permission of women be sought in relation to their private parts?"  He replied: "Yes".  Then I said: 'But a virgin woman when she is asked, she is shy and does not respond.'  The Prophet said: "Her silence is a sign that she agrees."

It is clear that this Hadeeth is about whether the permission of the woman be sought before her guardian marries her off (to somebody else), or could he oblige a virgin woman who is under his guardianship to marry without her consent.  The answer to this issue is already mentioned in Fatwa 162499.

In conclusion, the majority of the Muslim scholars, who are of the Maaliki, Shaafi'i and Hanbali Schools of thought said that it is permissible for a father to force his virgin daughter to get married even if she disagrees.  However, the scholars of the Hanafi School of thought said that her permission must be sought and that he cannot force her to get married.

In any case, this Hadeeth has no relation with the issue of marrying a second wife and informing the first wife about it.