Hey Life, so sorry that you are going through this anger. Sometimes I think I'd rather be depressed than angry, it feels like I can do something about it easier than the anger.
It's time, time to stand up and walk away. Time to live for you and your wonderful children. Living for you is not one night stands, that is satisfying to the ones you are with.
Of course, you know this. That is why you're here. Isn't it? I don't know how old the kids are but you probably should let them know you don't need to know about the cuddling, coffee drinking, moments. Are you asking them questions?
Look, it's so easy for us to be here telling you to stand up and move on, what you're going through sucks. And of course you are going to think he is happier and she is better than you, but really, she's not. She has the problems that he brings wherever he goes. I don't care how many times he's cheated WITH her, eventually he will be cheating ON her. That is who he is. All her horses and her big mansion is what is seductive to him in addition to the thrill of the affair. But, remember....... now that he is with her it is no longer an affair, its reality, they are together.
Take some time for you and only you, no one night stands and maybe no Mr. Healthy, maybe you should focus on you.