People will think I have odd ideas about this I am sure .....

Your relationship you have with your dad is just that. A relationship with your dad.

You are not his keeper and he is not yours, what he does is up to him. I would keep in contact with him

I have a sister who made her feelings quite clear to my mum, that if she re married (my dad died many years ago) then she would be very upset about it so my mum never even looked !