According to the Shari'ah the man has the right to take another wife. He is not obliged legally to seek permission from his wife. The wife however can show her resentment. It is very natural. She cannot be declared to have committed a sin. However, it would be very wise for the husband to take her into confidence. It is not very wise in the present day social set up to cope with the problems that arise later on. Therefore, one should not sacrifice his present family seeking to develop another one.