My intentions to let go completely worked out smoothly. The first two days were a bit more difficult to give everything a place again and to realise that his replay period is actually still not over (although I was pretty much sure of that this time) but that too found a place quickly.
He has contacted me a lot in the last week, with very mixed messages (sometimes angry, sometimes apologetic), the realisation that he has no control over me drives him crazy, but I have responded very firmly, and for two days in a row I haven't received anything anymore so he leaves me alone for now. We will see what the future brings.
I had a very good conversation with his father and he is more and more convinced that there is more to it. He told me that he can compare EXH to how he was before he was in R with me. Throughout his childhood, EXH has been a very difficult child, teenager and young adult, this ideed due to certain trauma's. He is convinced he is a narcissist, which is why I had to think about kml, who, if I remember correctly, had also come to the conclusion that her EXH actually always had it in him but was able to hide it for a long time.
FIL is convinced that this is the case. That he was able to suppress it for years because of the stability he had with his work and with me. At some point, the work fell away and he lost it, and this way his narcissism once again took a strong hold.
What it ultimately is, I guess the future will tell.
Meanwhile, the children are aware that their little half-brother will be around for the next period and the three of them have decided they want to meet him. They did make it very clear that they do not want to do this at EXH's house, as OW2 is also there, so I suggested doing it here at my house so that they can at least get acquainted in a for them stable and familiar environment and not simply somewhere random. However, I am still in doubt if I will be there. I have absolutely no problem meeting the little boy, I have given that a place already a long time but I don't know if it is "necessary" for me to be there. After all, I have nothing to do with that, but I would do it for the children if they feel it should be necessary.