OM are -- by definition -- PREDATORS. They are literally PREYING on your wife, and on your family, and on your family's finances, emotional and even physical health.
Who are you to sit passively by -- usually in just plain old-fashioned FEAR -- and have your family PREYED UPON by another man? Did you not say a vow on your wedding day to "protect" this woman? What the hell are you thinking? Is your fear -- and your co-dependent, "pleaser/conflict-avoider" personality (and I say this as a man who is BOTH) -- more important to you than your DUTY to protect your wife and your family???
I know what people are going to say: "you can't control another adult." No, you can't. But you can damned sure throw every conceivable thing you've GOT at it, and be the sheepdog that God intended for you to go when the wolf is at the door of your family.