Polygamy/Mutaa

Maryam asked 7 years ago

There is a muslim brother that is asking for my hand in marriage, and we are very compatible – except for one factor – he wants a 2nd wife.  He has had a mutaa contract with a girl for a long time (we’re both Sunni), but he wants to marry me and renew the mutaa with this girl in the process.  He said that he would eventually have a nikah marriage with her, but I also don’t feel comfortable being a co-wife.  How do I convince him to not want multiple wives?