Its just not your business is it :)
It has nothing to do with you.
You wont accomplish a thing but come across as a scorned ex lover.
You can live with yourself by understanding that you are responsible for yourself and your own behaviors and no one elses.
Take the high road on this one and keep your information to yourself.
Its none of your business and you want to tell his wife because you are still in love with him and you want him to hurt as much as he hurt you. Nothing to be gained in this.
Ethically and morally it is wrong for you to talk.
Find a way to heal and move on with your life.
I know you don't like my response any more than you did my colleagues but it would be unethical of me to lie to you.
Its just not your business, its his and its hers and not yours.
Heal, move on and feel better.
I know your heart is broken and you are in great pain but you will feel so so so much worse if you wreck vengeance.
You take good care of you
Warm wishes on such a painful post.