Thanks you all for your advice and guidance...means a lot. So, I will keep my confrontation to just telling her that she has not deceived me and I know the truth.
She is already talking to lawyers and planning to marry the OM. This is what I heard from her conversation with OM. Also, I dont think there will be tears or anything as she has already said that she hates me for what I have done in the relationship and has been really cold toward me. Not cooking food for family (just makes her food and for daughter), not talking to me, nothing.
Don't know what will happen, but I will keep you guys posted.
Thanks again to this wonderful family and great support.