Ok someone explain this to me.

So, from my previous post about my divorce I officially was told by my ex-wife that she is exclusively seeing someone. The reason why she told me is that our son overheard a conversation she had last night with her sister. She didn't want me to hear indirectly. What she did not know is that our oldest son (I have 2 boys) already told me weeks ago and I had my suspicion about it over 2 months ago.

I was told this by her at like 7:30 in the morning. (Not sure why you wanted to start my day off with this but fine.) I said that it's too fresh for me to hear that and I would like to stick with just talking about our youngest going forward, to which she agreed. Then went to state that she is going to hold off for "a while" introducing our son to this new person. A while her world could mean next week or tomorrow with the way she moved on so quickly.

After that b.s., arguing with my best friend about bs, and then having my son be called the "n-word" at school... I broke... I got teary-eyed and couldn't hold it all in anymore. I got in my car, put my face in my hands, and just... cried... Too damn much to deal with in one day...

Here's what's weird about all this. Once the day was over and I did some retail therapy (lol), I thought about what she told me this morning and I feel.... relieved... Why? Why does this make me feel better? Closure? Karma? What!? That part is tripping me up...

wow ... i got a lot of "vibes" from reading your post that might be of some help to you figuring this out.
one thing is that now that finally fessed up and told you the things you already had a hunch about, by her owning up to what she shes been sneaking around behind your back and hiding from you all along gives you the "relief" of finally getting that justification you deserve.
also by her saying shes gonna wait b4 introducing your son to her new " mr wonderful" it kinda seems like maybe now her wonderful new life without you that she had her hopes set on happening might not be as peachy keen as she planned on so shes been having some 2nd thoughts about what she did & maybe her life with you wasnt as bad as she thought it had been.. & now shes thinking about what she gave up only to wind herself up in whats starting to look like might turn out being an even less than ideal spot... all of which gives even me a touche kind of feeling so perhaps deep down you see it as the start of her getting some of the payback shes got coming her way and gives you a wee bit of some satisfaction out of it.
also now you two are divorced, your not wearing those rose colored glasses anymore so now you are able to start seeing her in a whole new light and shes beginning to look a lot less of the woman you had once believed deserved to be put up on a pedistal to you now and gives you a little "good riddence" glad shes gone feeling.
so yes, karma, closure, justified, satisfaction, vindicated, ...

I wish that was the case. Normally I think when it comes to introducing someone new to a child is because you want to make sure that this works out before placing your child in a world of confusion if the relationship doesn't work out. Then again, I can't be 100% sure.

exactly! sounds to me like her perfect little pipe dream of this wonderful fairy tail life without you aint quite going according to plan

Not sure where you are getting this from. I can't read that she has any regrets anywhere.

Anyway, I think your relief comes from her having moved on and you being off the hook. You owe her nothing. Take care of yourself