Darude,

What’s your source of information????
It is no where mentioned in any Hadith, that a Husband should seek permission from his wife for another marriage (or any other thing).... and ya a Woman always has a right to ask for diviorce but with a valid reason, and her disapproval for her husband's second marriage is not a valid reason according to Islam until it is mentioned in special clause column in the marriage agreement signed between bride and groom .

Take care

“We make a living by what we get; we make a life by what we give.”

Sir Winston Churchill