GTTM,
Oh dear. I am so sorry this happened. Your wife know clearly how you feel and she obviously wants to get it all out into the open. It's awful this argument happened in front of the kids.
I really feel for you. It really looks like divorce may be on the cards, unless you fake it for her which I don't think you will. Besides it won't be any good for the kids if they already know how you feel and that WT is breaking up their family.
Think things through clearly and try not to have a messy future. My divorce was a nightmare and if I can help you in any way to make things smoother for you I will.
Thinking of you GTTM.
Take care
Kate xx