this same situation happened to a friend here in Doha. she & her husband were both from Phillipines, married for 15 years with children. He had an affair, she refused to divorce him (Christians can't divorce in Phillipines anyway) so he spitefully converted to Muslim to marry woman #2. To convert to another religion to marry a mistress has to be one of the lowest things a man could do in my opinion. God will make it right in the end.