I'm going to also step in on the OM in my case. The OM had a criminal record "a mile long" from what I gather...and in it was a child endangerment charge. The ex sent pictures of my kids to him and was calling him her future husband. Remember way back when I talked of how the ex was in the "bad boys" and how our MC talked of that, too? Well, he fit the mold that she knew for most of her life. So, one of the things in our custody that I had included was that they are NOT to be around people with criminal records.
My lawyer is well aware of the types of people she was around and all and made sure specific wording was in our agreement that forbid it. The ex wasn't really happy but she signed it without a fight....because she knew who held all the cards.
There are moments in this life when you are so confident in the rightness of your actions, that not even for a second do you consider the option that you might be wrong.