Gifts of Knowledge

Shaikh Uthaimeen, may Allaah have mercy on him, was asked, “I want to get married to a second wife, is it permissible for me to marry again secretly without telling my first?”

So he said, “It is permissible for you to marry again and not tell your wife about it but the nikaah must be in the open and something announced [i.e., not secret], because the Prophet صلى الله عليه وسلم ordered that saying, “Announce the nikaah.”  And when you do what Allaah and His Messenger have ordered by announcing the nikaah, then Allaah the Most High will make your wife pleased with you when she finds out.”

Fataawaa Nurun-ala-Darb.