DH's parents split up when he was 6 and his sister was 4..His mother remarried and had 3 more children which are treated completely differently to DH and his sister.
His father couldn't take the responsibility of children, often standing them up or disappearing. He is an alcoholic. Several failed dysfunctional relationships. However he has always been fine with us, DH even had him as his best man.
FIL then moved in with his parents and then became their carer. They have both died over thr last 2 years.
FIL has now become obsessed with them, their money, ideas of family, and DH's mum. Sporadically DH received horribly abusive messages saying he is never going to talk to us again, we are 'fucking users', had the 'fucking cheek' to do x, y and z. This is usually followed by an apology. DH is the nicest man you could meet and doesnt deserve any of it. However he will always forgive and be prepared to meet up again.
WIBU to say this man is not welcome in our home or around our children?