We became step-grandparents a few years ago and couldn't have been more thrilled. As far as we are concerned, my son's stepchildren (he doesn't refer to them like that but as his children) are our grandchildren in exactly the same way as our biological grandchildren.
We feel honoured that their lovely mum has so warmly welcomed us into their lives and hope to do a good job as grandparents. They are children who deserve to have as many loving adults as possible in their lives, and the fact their parents split up and their mum now has a new partner is absolutely nothing to do with them or how anyone should treat them in the future.
Yes, they may get trips or inheritances from the other side of their family. I can't see what that has to do with me. They're my grandchildren, and they'll get the same trips, treats and future inheritance as all my other grandchildren. We wouldn't have it any other way, and luckily our other adult children agree wholeheartedly.
I do understand the argument that if our son and his now wife split up, we may run the risk of seeing the children less. But anyone who gets to the age of being a grandparent realises that life unfortunately brings the odd unpredictable loss. You can't make your own life smaller by living as though those losses are inevitable.
If it happens, we'll deal with it at the time. We refuse to diminish our joy in our grandchildren and the time we spend with them now in case something goes wrong in the future.
And in return, we are so lucky to have the joy of being a part of our beautiful grandchildren's lives. We definitely feel like the winners here.