***UPDATE*** Dad organised with Solicitor to update Will, specifically stating that Wife not to have UK assets (with a supporting letter saying he had gifted properties to her which create rental income for her in Thailand). Wife totally lost it with Dad  with Dad ringing me up very upset.  Will yet again rewritten this week with her receiving ALL assets in UK and Thailand.  
Feeling confused, upset and very let down by my Dad at present.  His explanation was that she needs a house to live in when she gets her Citizenship.  So trying to keep a stiff upper lip to support him through illness without wanting to throttling him at the same time!

 

If you are in a situation where you have a new wife and children from a previous marriage PLEASE speak to ALL family members with regards to inheritance before sickness/old age takes over so they can get used to the idea beforehand of who gets what and your reasoning behind it.  AND make sure those Wills are up to date.

 

Thank you all for taking the time to comment positive or negative as it enabled me to research and wrap my head around a few things.

What you want us to do? His money his choice. However if you hate his wife tell him to do will in secret. Tell him do the right thing by his kids but keep quiet.

 

Best deal in silence. Move like a tiger. The world is full of crooks, greedy takers.

 

Do not trust anyone with wills. Know who the enemy is in advance, negotiate in secret. Grind them into the dust in silence.