Sounds like he already has and that the
OW has been the OW fir awhile.

Too often the person that wants to be nice and stay friends has a calculated plan to keep the trusting partner (you) in the dark and off balance as they proceed with a premade divorce plan

What he says or thinks about you is none of your business. You have to start focusing on yourself. Get a lawyer, financial advisor and a therapist lined up. Make sure that you cover all your financial needs. He is making himself look the victim. Do not play into that. Whenever you see him, just smile and walk away. Hugs my friend.

A fast relationship will likely end fast... Also, a relationship built on putting someone down is not going to be of value.

I know that must be painful. The most mature thing to do is to try and separate emotion from the event and think cognitively through it. That's extremely difficult but you'll see that he is choosing to handle the divorce and grief without going through it, but avoiding it. He's not going to grow, and that will cause him more pain later.

Keep yourself focused on you. I know this is absurd but when you can get to a point to forgive him, it will help you in the end.

Cheers

After 12 years, he's not replacing you. He's only thinking of himself and in his new life moving forward, he's secured his next step. I know this well. After 20 years for me, my spouse secured his new life without me, acted as if he truly cared to keep me off balance, and, like refurb stated -- he had his premade divorce plan because he has a new love in his new life. So be it. He stopped caring for you because he cares for another. This speaks to him about his lack of honor and integrity, and, who want to settle for someone like this?

Do not get caught up in what he's said to this OW. He is justifying him leaving you and is clearly making you the villain to this OW. This allows her to feel sorry for him while she builds her life with this new man who remains married to you while residing under the same roof. My spouse did the same thing, and, she's foolish enough to believe it. They deserve each other and I deserve far better.

Getting along is better than fighting. Use this to your advantage and focus on yourself.

That's how my stbx said too about our split... we won't be like others I'm going to do blah, blah, blah...changing every time we met. Guessing the OW coaching him on. We were together 25:yrs and 3 kids. The thought of passion and butterflies has had and got him.
Take it from me, I've always worked and contributed too. But make sure you are fighting for you. When he said things wouldn't change....well neither were vows and comittment to marriage and family. But he has proved to me things do. I trusted him fully and when I put it all together about OW more than friend/employee, I still tried to save my marriage and family. But after ten months, I gave up. I beat myself up with all his justifications of what I did and didn't do. Don't lose you or your set esteem. Someone that treats another that they committed to is not worth it. Hugs and prayers to you. Don't waste anymore of your time on someone who doesn't love or care for you.

some people just run from their pain rather than face it. sounds to me like he is plunging ahead with someone else, in part anyway, to mask the pain of divorce. he may feel he needs to put you down in order to earn her trust, or she may encourage him to put you down and he goes along so she will stay, there are many possible scenarios. also, if he already had one foot out the door in his mind, he may have done some of his grieving already. who knows. it's never easy, that's for sure. i found messages from my stbxh to multiple women, just days after we separated, while he was txting me saying maybe we should keep trying to work on the marriage. finding these messages to other women, saying he's "getting separated and finally going to go after what makes [him] happy" was a really tough blow. but, looking back now, that's what really cemented in my mind that he was 2 faced, putting on a show for who ever he was around. and even though it was awful at the time, it gave me a crystal clear picture to hold onto in the times that he tried to come back over the past year. people who do these things do so because they don't have a healthy way to cope with their feelings of loss. they don't want to grieve, they think jumping into something new with someone else will let them skip the grieving process, but it doesnt. sorry to hear you're going through this. you will go through an emotional roller coaster, we will be here for you, DS has been a life saver for me, especially in my early days.
Big Hugs
(((HUGS)))

I'm sorry you had to see that. It must have stung. Use this as the fuel you need to move forward and get the best possible settlement for yourself. Since he is disrespecting you behind your back, but maintaining a nice front, what else could he be hiding? Secret accounts? I disagree with the comment that it's "none of your business". As long as you are married and living under the same roof, the fact that he is not really who he pretends to be, is very much your business. Now use it to your advantage. Taking care of your own needs will make you feel better.

Jbuck hit it right on. I don't thin he is replacing you, just running nad hiding from the pain while you face it head on. This very hard stuff to go through- just keep in mind why you are separating and keep trying to turn your negative thoughts into positive ones - I know its hard and takes lots of practice, but this is a process and you will work through it. Just remind yourself that his choices now have nothing to do with you, his way of coping. Take care and don't look back.