Me: [whispering] Hey Dad, how old is Grandpa?

Dad: ... Dad, how old are you?

Me: O___O

Grandpa: Uh... Almost eighty.

Mom: No, he's not that old yet! Mid-seventies at most!

Grandpa: Uh... well, I was born in year 25 (ROC).

Dad: You're seventy-five.

Grandpa: [nodding and returning attention to television] Oh.