Not sure if I am being a jealous old cowbag here. Feel free to hit me with it.
Split up but he's stalled the divorce as he wanted to keep the family home for himself and needed to save up to buy me out. (I won't be getting 50:50 either more like 25% after 25 years but that's another story.) I moved but he did not want to split all the stuff at the time - eg the sentimental stuff like photos, baby boxes, stuff in the loft etc and it was agreed we'd sort this out at the time of the divorce.
We both been on our own for a while. He introduced a new partner to our 4 teenage DC. According to the DC she is significantly younger, prettier, thinner, more intelligent and pretty much better than me in every single way. (I am actually happy he has moved on - I instigated the split but nobody else involved on either side). None of that is a surprise - men in their late 40s typically want to date women 10-15 year younger than them. DC spend a lot of time telling me how great she is and spend a lot of timing complaining my house is too small, I have less money than dad etc.
What I am a bit miffed about is that ex gave his new GF's preschool child, sentimental things I had put away from our DC in memory boxes, some of my DC's books (again I had put away for when they had their own kids), one of their christening outfits and very strangely some of my books (rare and valuable).