Crystal, I wouldn't have sat back and pretended I didn't know either. That is not my brand of honesty either and it does matter as he is also responsible for financial support of the kids.
I think I am at the point on my path where I can say things without all the emotional reactions and just address the facts.
I do know that I can only do that by maintaining my well being and a healthy distance and set of boundaries.
wishing you all the best.