Sally, I can assure you he will NOT have a happily-ever-after with his gf because all the sh*t he put you through, all the abuse he was capable of - he is still that guy. He'll put her through it too. Or she'll put him through it or they'll torment each other. Karma is a bitch as they say and it's true, although it may take years to see it.
I've been through this with 2 ex's. One was only a few-months bf so not particularly intense but he dumped me for another woman. The other ex- now that was VERY intense, that was years, we were soul-mates, etc. But he dumped me for another (younger) woman.
Years later, at different times, BOTH these guys begged me to come back. Repeatedly. The women they dumped me for were long gone. I happily refused as I am with a wonderful man who I trust completely. I shudder to think of what my life would've been with either of those ex's.
Fwiw, I've maintained a friendship with both. I never thought in a million years that would be possible - but it is.
As someone else said, the best revenge is living well. Live your life well. You deserve happiness and you'll get it. You won't always be so angry, in fact a day will come when you could care less what your ex is doing or who he's doing it with.
God bless...
