I know all about the pain of ongoing affairs. Sorry about that.
I think this is the time to ignore and treat your wife like a distant friend. Someone you would be polite to, but would also keep your distance as well. This might help you detach. Nothing good would come from outing her/cautioning her about her safety, I just don't think it would be the right time. You can't shelter her from her cheating boyfriend...
But.....kids first, kids first, kids first. Document and make sure they aren't around him when he is drinking, drinking AND driving, and that he is appropriate around them. Another poster here mentioned OM being in a towel around his kids, just soooo wrong...
