I was the other woman. Should I tell her?

So basically I was dating a guy for 2.5 years and it wasn’t until about 6 months ago that I started to suspect he was married(it took that long for many reasons I won’t get in to). I confronted him, he denied it and then broke up with me saying he needed to focus on his new career. We stayed in touch though and me being the dumbass I am, slowly let him creep back into my life even though I didn’t trust him. I finally reached my breaking point last week and brought up every single thing that was bothering me and presented all the evidence I had that he might be married. He blew up and it just turned into a horrible argument, still denying everything and/or avoiding my questions/concerns. It ended with me saying I was done, I didn’t want to talk to him anymore.

My question is, should I tell his wife? Or let karma do its thing...

And please, don’t crucify me for this... I already feel like complete crap about myself for ignoring warning signs and letting it go on for so long 😞

*clarification* so my friend found her on social media( I knew who his supposedly ex wife was, that had come up early on but he had said he was getting divorced), and while she never posts pics of him(he’d never let me take pics of us either) there was enough evidence pointing to them still being married(I.e. scenic pics from the town he lives in, his dogs, saying his name in a video) and then I saw a pic that had his hand in the corner of it- showing the ring he always had on. And it’s a unique ring... (He told me it was his grandfathers ring every time I asked why he wore a ring on *that* finger).

I have been so confused because yeah, he keeps denying being married, why would someone do that?! But this evidence just keeps piling up that strongly suggests he is...