Wa `alaykum As-Salamu wa Rahmatullahi wa Barakatuh

 

I empathize with your situation. The man has betrayed your trust and breached the terms of your marriage contract since he told you that he wouldn’t take a second wife while being married to you. Therefore, you have the right to divorce him Islamically, if you so choose.

 

If, however, you want to keep the marriage, you may do so while bearing his behavior patiently. His actions are born of lust and passion rather than his commitment to Islam. He cannot use Islam to justify his actions which violate the teachings of Islam.

 

Having said this, whether you divorce him or agree to reconcile to the fact of his second marriage, you cannot sever blood relations: you cannot stop him from seeing his son or prevent your son from seeing his half-brother or sister for after all they are blood relations.

 

You need to turn to Allah for strength and peace. I would advise you to get a copy of the book, Invocations of God by Ibn al-Qayyim al-Jawziyyah.

 

I am sure you will find it a real source of spiritual strength.

 

Almighty Allah knows best.