Many kids report later, as grown-ups, deep resentments over not being told the truth. It's a very difficult, personal decision. I decided that IF I was going to err, I was going to err on the side of the truth, and let them know that I would ALWAYS tell them the truth.
You're not painting their mother as "bad." You're letting them know that she's flawed, just as we are, and that we still love her, very much, but that we cannot remain married to her as long as she refuses to stop having a boyfriend.
