Mike,
I am very sorry that your wife has made a series of bad decisions and betrayed you. You did nothing to deserve that, and if she thinks that she is going to have a good life with a man who has already served a third of his life in jail before the age of thirty, then she has rocks in her head where a brain ought to be.
When you write this...
If I go to a lawyer with what I know I’ll wreck her life which will wreck the kids lives which will wreck mine too as a result. I’m stuck and also going to get threats from him and I’m pretty soft...If I put this into a lawyers hands I honestly think she would kill herself or something and I could never live with that on my hands.
...you are engaging in 'catastrophizing', which is a process of fixating on a worst-case scenario and then convincing yourself that it will happen. What if there are other options?
For the sake of everyone concerned (yourself, your wife, and your kids) you really should see a lawyer immediately and seek advice about what can be done.
It sounds like you are no longer living at home, or she has moved out, and that arrangement in itself can have legal ramifications that you should discuss with a lawyer. For example, a parent who moves out of the family home can, in some circumstances, be deemed to have abandoned their family. Please, Mike, get some clarity on that.
You say that your wife "lets" you see your children whenever you want, but she has absolutely no right to prevent you from that, so it is not an act of generosity on her part. In fact, if she ever tried to prevent you having access to your children, she stands to land herself in trouble.
Mike, going to a lawyer and protecting yourself and your children is not 'wrecking' people's lives; it may actually prevent your wife from wrecking everyone's lives. She is clearly living in a deluded fantasy, and her capacity to make rational decisions is questionable (to put it politely).
And what makes you think that a jailbird without a career or any legal talent for making a living is going to want to be lumbered with your wife and two kids to support?
If he went inside when he was 18, he has had nothing more than a few teenage girlfriends. How is he going to cope with some other guy's wife and kids making demands on him? If your wife is deluded enough to try setting up home with him, it will not last six months.
Seriously, the best thing you can do is see a lawyer and burst her fantasy bubble with a dose of harsh reality. There is nothing to be gained from letting her pursue this silliness, particularly not if she is going to drag your kids into it.
And you should also talk to the lawyer about how to handle threats from that guy, because if he gets released and starts threatening people with violence, he will be back behind bars before he knows it.
Frankly, I think the best thing you can do at this point is to contact a lawyer, get him to draw up divorce papers, and have him write your wife a letter setting out all of the legal consequences there are likely to be if she pursues her current course of action.
If doing nothing lets her wreck the family and embark on what is bound to be a disastrous and short relationship with an ex-con, then doing nothing is not doing anyone any favours, is it?
Which means that doing something, and taking action now, can prevent something worse from happening.
You have every right to talk to a lawyer. You have every right to protect yourself and your kids from your wife's recklessness. You should use those rights, Mike, and a lawyer can show you the best way to prevent this lunacy from doing any more damage than it already has.
Nice guys can fight for what is theirs, and what is right, can't they?
Mike, everybody here is appalled by what has been done to you, and we all want to do our best to help you fight it and prevent it running out of control and causing a train wreck.