Became Muslim, left wife and married another in a Muslim country

My son was initially married in the Philippines, physically separated but not legally, became Muslim but not practicing and in paper only and got married with another woman in a Muslim country in the mid East. He is now in the US with his 2nd wife and kids; no contact with the first one. Can he be in any trouble if the first wife finds out and give him any problem? He is planning to get married with his 2nd wife in the US, in a church, that is why I am worried. Is his being a non-practicing Muslim give him a problem, though he is Muslim in paper. I know Muslims can have many wives.
Thanks.

In the US he can only have one wife even if he is Muslim.

To marry again would be bigamy which is a crime. So he needs to clear up his first marriage or not marry again--or not live in the USA.

Sorry, I might haven't presented it clearly, but he is marrying his 2nd wife that he had in the mid east in a proper wedding ceremony in the US and not marry another woman again. His problem is with his first wife that he married in the Philippines as a christian before. Can his first wife run after him for bigamy, being muslim now, and in the US.
Thanks again.

i also got married to a muslim revert who when he was still christian is married to another filipino (civil) and not yet annulled. we have a marriage certificate but as i talked to a lawyer she said in philippine law our marriage is null and void because the first marriage regardless of what religion is legal and binding unless annulment is granted for the marriage.