I called all three of my grandfathers (mom's parents divorced and remarried long before I was born) "Grandpa" to their faces, but if I spoke about "Grandpa" at

I called all three of my grandfathers (mom's parents divorced and remarried long before I was born) "Grandpa" to their faces, but if I spoke about "Grandpa" at dinner, I still needed a way to specify which one.