Ladies, I just found out my dad was a serial cheater. What do I say to him?

My parents have been together for over 45 years. My mom and I have a wonderful relationship; she's still with my dad, says she loves him, believes he is totally in love with her, and yet.... Today we were talking and she finally came out and said that for the entire time I was growing up with them, he had multiple relationships with other women.

I knew about one woman, once, a very long time ago, and as far as anyone told me that was the end of it. Today I found out otherwise and I'm trying to process all this and failing badly. Apparently, my dad had many extramarital affairs and now talks about it publicly as part of his "sinful past" and somehow I'm the last to know.

My parents have a business together where they are paid by churches to come and talk and do whatever else the heck they do. They do it together, it is international, and they make a decent living at it. One of the things my dad talks about, and I'm just finding this out today, is that he was a serial cheater back when I was growing up.

The way he tells it, is that spirituality turned his life around and now he's this wonderful person and has this amazing marriage with his wife (my mom) and isn't god incredible... blah, blah, whatever. The part I'm fixated on is where apparently the entire world knows he was doing all these things while I was completely ignorant of it when I was growing up in the same house as him, AND when he finally came clean about it all of it to my mom, no one thought I should know anything, AND NOW it's part of his little dog and pony show. Anyone who goes to their meetings might hear him talk about this... I seem to be the only person in the world who had no fucking clue about the extent of his lies and deceit.

My mom and I talked about this all afternoon today, but I told her I really wanted to hear from dad. I don't imagine this is a conversation he wants to have with me; we don't have much of a relationship to begin with and we never talk about anything important or meaningful. I think I'm angry that he lied to us for so long, and that he'd come home from these affairs and look me and mom in the eye and say he loved us and then acted like he was committed to the family. I think I'm angry that he betrayed our trust, and I'm definitely extremely upset that I'm just finding this out now when mom, and apparently the entire world except for me, has known this for about 20 years.

He's probably going to find out tonight that I now know all of this now and will most likely call me tomorrow or sometime this week to talk about it. I don't even know what I want to say to him or what I hope to hear. I'm angry, I feel betrayed, I don't trust him and I feel like a fool for being the very last person in the world to know about any of this. What do I say to him? I want to have a conversation... we just don't have much of a relationship to begin with and this has a huge potential to either discuss meaningful things or alienate us further from each other.