My Wife Got Married to Another Man!

Good day Amara, I must confess that I have never come across anyone with the kind of wisdom you have in counselling people. What do I do ? Please I need your advise.
I got married to a lady I dated for three years before travelling out of the country.
In 2011, I returned to Nigeria only to discover that my wife was keeping extra marital relationship.
Due to anger I left her and went and rented another apartment. Not long I met an old female friend and before I knew it we started dating which resulted to pregenancy and she gave birth to a set of twins ( girls).
And I love my kids so much, although my legitmate wife have not given me a child and now she is currently married to another man without divorcing me.
What should I do now as I am already living with the mother of my twins and my kids?

Since your legitimate wife has gotten married to another man, all you need to do is to go to her family, demand for the dowry and officially file for divorce to enable you remarry the woman who had set of twins for you. 
Maybe you may need to learn one or two lessons from your experience. 
What flows through the veins of a woman isn't "holy spirit" but blood and water, you don't get married to a lady and travel outside the country even though you may have good reasons for your action or you may have good communication with your wife while there. 
Every month, she ovulates and that's a lay man's way of saying that she's on heat simply desiring sex from her husband. 
If a handsome husband is in US making all the cool cash and possibly helping himself out with some white babes out there, please what becomes the fate of his own wife who's weeping every night trying to manage her legitimate urge for her husband? 
Yes you had legitimate reasons to be angry with your wife if your evidences were true but how will she bear children for you when you were outside the country or do you think that once you have sex, pregnancy occurs? 
Will you be honest to say that you never cheated on her, that the best option to resolving the issue was renting an apartment for you to accommodate your old flames? 
I feel that wasn't the best approach but that notwithstanding I feel that you should make amends where there's need to so that such doesn't repeat itself in your marriage. 
Wherever you go, if possible please go with your wife, she needs you much more than she needs your money. 
Whenever there's an issue in your marriage with your wife, please do not rush out, seek for ways to resolve it,separation and divorce should be the last option after all other efforts have failed not the first option. 
Take your time to organise your life and focus on your marriage so that you don't spend years pursuing shadows of love.