Rob, As painful as this must be, at least you now know where you stand with W. Hope your L acts on this. It sounds like your W feels she can justify anything she does. Maybe you should not discuss it with her and just go through your L. Did you even suspect this relationship? I think anyone would agree it is not a good idea to expose kids to boyfriends/girlfriends until it is sure that it will be a permanent relationship. It is so unfair, it confuses them and makes them feel insecure. If your W had half a brain she would have given you D for the weekend and kept her affair private. She is behaving like a whack job, without any regard of how it will effect a 5 year old. I so hope there is some legal movement soon for you because it does not sound like you can reason with W.