My wife and I were at a doctor's appointment and her Mother (NeNe, who is in her 60s) and my wife's brother (Uncle who is almost 20) were watching our kids.
The following conversation took place and only the names have been omitted to protect the innocent, zinged and embarrassed.
Uncle: Do you know how old I will be on my next birthday?
My Youngest (8 yrs old): hmmmmmmm.......You will be 20
Youngest: Wow, you are OLD!
Youngest: What are you laughing at? You're like 80!