revealall and how do you think my DH coped, or his 2 younger siblings?
Don't be daft, I didn't have anything to do with it at all... but my DH had to. And your 'what if...?' is exactly the situation they found themselves in... as I have said. Their youngest sister is 28 years younger than DH.
It didn't hurt anyone. No one had to cry, feel pushed out, unloved or, as katty seems to be, embarrassed. They just got their heads around the reality... their dad was shacked up with a much younger woman! His life, his choice.
And in his experience, they had 20 years of happily married life. So in my experience, it has every chance of working!
Katty, take a deep breath. You can't change it, it is happening. But you must change how you see it/react to it, or your relationship with your dad will suffer. How he gets on with his young girlfriend is his business. You have no part of that.