I have been researching this all day... and Brit is right.

Islamically he does not need his wives permission but it is advised he tell her.

You may be confusing civil and shari'a law. In Egypt, a civil law was passed requiring the written consent of the wife for a man to take a second wife. This may be the confusion, I am not sure of the law in other countries but Shari'a law does not require any permission.

"Diplomacy is the art of saying 'Nice doggie' until you can find a rock - Will Rogers"