I haven't had any contact with my father for almost 20 years. He left us when I was very small and we had regular court appointed contact so saw him every other weekend.
He has never been a particularly good father figure - psid minimum maintenance, often late, always trying to wriggle out of it leaving us in poverty. Never contributed emotionally, financially or logistically. Mildly EA - taunts of being fat, constant using of us as weapons, nasty calls, threats to take us away from our mother, malicious ss reports etc.
I was frankly relieved when I stopped seeing him at 18.
Anyway, all fine and dandy until this week when I answered my phone and it was him. He had 'tracked me down' (I live abroad, phone and addresses are public records here so I can't withhold this info and there's no point changing my number.)
Cue a long rambling monologue about how he's thought about me daily (doubtful) and plenty of self pity. No apology for being crap, no acknowledgement that he never bothered with us. Etc.
I know why he's called. His mother recently died and I recently had his first grandchild. Since then things have been arriving in the post.
I'm extremely worried they are going to turn up on my doorstep- they have form for 'gestures.'
Over my dead body will they see my son. They blighted my childhood and they are not doing the same again.
So just a rant really 
Any tips on how to relax a bit about this? It's really stressed me :(