ThreeTimesALady... Do NOT do this. You will not achieve anything from it except a phenomenal amount of damage and you will have no control over what happens, none at all. Your married man will close ranks with his family, he will shun you and you will be left hurt and angry and clueless because he will not contact you again. Expect no other outcome.
Then you have your own family crisis to deal with... expect your marriage to be over and some messy, painful times ahead whilst housing and custody is sorted out. You will have no control over that either.
You've embarked on a most destructive course of action. Affairs are never painless, there is ALWAYS pain for somebody, somewhere. At the moment, you still have control of what happens now. You're already at the stage where you want more and you'll never have that. Even if you and the married man decided to leave your marriages now and set up home together, you would be dealing with a 'deficit of relationship'. Some couples can weather that, acknowledge what they did and grow the relationship from a new position of honesty. Most cannot and are left wondering what the hell happened?
This is not what is going to happen anyway. The only choices you really have are whether to confess to your husband. I would forget all about telling the married man's wife; that's for HIM to do, not you. Your priority is your own household.
A two-year affair is a significant time of deceit; even if you only saw each other once a week, that's still been an enormous distraction for you both. Your married man will probably continue if you wanted this too; you're fairly 'stable' in terms of having kept your own counsel for this length of time and it's risky - so as far as he is concerned, you're quite a good bet. You could turn it the other way just as well, ie. you know that he's not planning to lob a grenade into your homelife. You can't cope with this now because you want more; he will not give it to you. It's not him that's changed, it's you. Your expectations have changed and in effect, you've moved the goalposts. You will not get what you want from this man because it's true, he would have made overtures of leaving his family before now had he wanted this; he didn't.
Are you going to go ahead with this madcap plan of telling his wife? You really shouldn't.
Are you going to tell your husband? Ultimately, that's up to you, but if you can't keep this inside, write off the affair and throw yourself into your marriage, husband and children, then perhaps you should.
If I were in your position right now, I'd take some time to work through the scenarios in my head. There is no painless one, not for you. You're too invested and your feelings are going to be trashed either way. I would, if I felt that the affair was something I no longer felt happy in, would end it. That's one relationship that you can walk away from with your head erect because it's the right thing to do. Having made a decision to end it, I would tell married man 'no contact, or else'. He will get the message and won't bat an eyelid. His relationship with his wife is his own concern.
You could do that right now, it will give you valuable thinking time to decide what you want for your marriage, husband and children. You said earlier in the thread that you weren't sure whether your marriage was 'bad' before or after the affair started... nobody can know BUT I can guarantee that your marriage hasn't been helped in any way by the affair. Men can be quite good at compartmentalising relationships; some women are generally, wired up differently and it doesn't work in their favour when it comes to extra-marital relationships.
Accept that there will be pain in bringing this to a conclusion; make it your own as far as you possibly can, ThreeTimes, that's the only thing you can really do now. I'm sorry for you.