New to this. Is it really MLC or just an affair?

[Lone77]

Ok so somewhat of a development, H 'text' to tell me that he's 'recently found out that I am expecting a child later this year'. Yes done by text but then the end of 21 years was also find via this method.
He told our D (18) the same night although she was with me when I received the text and so knew before she met him. D is devastated, mortified, embarrassed and a whole host of other emotions. She said H switched back and forth during the convo between being matter of fact about it, referring to his 'new life' and whether she still wanted a relationship with him. The next minute she said that he was actually sobbing with lip quivering the lot, saying how he wished he could change things and turn back the clock!
This for me is the end of DBing, I will not take on any part with someone else's child.
I've not cried, I'm not upset, I'm angry and I half expected it. They'd have been together for 3 months when she conceived! He's 40 with no home of his own currently (I'm still living in ours with D), already has a D who is 18, is still married and can't start divorce proceedings for another 18 months himself as he cannot cite the 2 reasons needed and I question how well they know one another in such a short time when they're not full time co habiting.
H is selfish with or w/o MLC tendencies and we'd agreed we didn't want more children as we enjoyed our financial stability and travelled a lot and ate in some of the best places and had the best of everything. Financially he will obviously see a huge impact and that's now my main concern, enduring my D and I are covered as far as possible now that this additional financial strain for him has developed.
When he did the ILYBNILWY he was in search of something exciting, he wanted freedom and a carefree existence. He wanted to know if there was more to life than what we had and now he's just recreating the whole situation but with the guilt, the shame, the embarrassment and obviously with my D trying to cling on for any little bit that he's willing to share with her. She still barely sees him and he texts sporadically.
I actually pity him, even if he's showing excitement or happiness at the news, I suspect that deep down there is a part of him that will be devastated. He loved that we'd been young parents and now he's starting again almost 2 decades on.
I sent him an email the night he text me. I've set out some financial requirements and I told him that this would be the last contact I had with him and have asked that he does not contact me again, save for any financial reasons.
Whilst I was prepared to try and work at things and had stepped out of the picture in the hope he would one day wish to reconcile, I cannot forgive this and I will not have any further involvement with him save for any practicalities of division of assets and then milestones with my D when I will have to see him.
D has made it clear to him that she will have no involvement with his new child nor the OW.
In a weird way this has given me closure. Whilst I wasn't sat here waiting and have a very active and fulfilling life anyway I was still in a limbo land where he was concerned, I was standing in the hope he'd return one day but never knowing how it would turn out. This clarifies that and makes the situation final and one I can propel myself forward from.
He has eventually transferred a sizeable number of the shares that were held in his name to me so this gives me some peace of mind and I'm financially secure.
I believe that he will live to regret his decision still, whether he can build a relationship with my D again who knows but I know that he and I will never be together again. I'm comfortable with that and whilst this time last year I wouldn't have wanted it I'm in a good place and capable of dealing with the situation. I will make the rest of my life the best of my life. While he's changing nappies, having sleepless nights and preparing feeds, I will be living life to the max. In a weird way the freedom and excitement he sought has now been handed to me and he's even more bogged down than he previously was.
I'll come out on top and I'll pull my D through with me