Who is my soul-mate.....................…

I am married with an illiterate lady. She is honest , loving, caring and trustworthy. She is ever ready to sacrifice for me. But in the silent corner of my heart, there is something missing. I do not know what. There is another lady, she knows that I am married but she always have soft and cool feelings for me. She has blinked her Eyes showing that she want to be mine forever. I do not know ,if she is truly wanted to do. She is masters in chemistry. I am puzzled . Please advise. I am muslim and can have 4 wives at a time.