When I was a teenager and I was painting my nails, my dad happened to be taking a nap in the recliner. My dad always said he never napped, "he was just resting his eyes". So to test his napping ability I decided to see if I could paint at least one nail without waking him up.
I was quite stealthy and I carefully applied a coat of clear nail polish to his right thumb. Dad didn't wake up. Dad didn't notice the polish on his thumb at all that day. In fact it wasn't until the next morning as my dad was standing in church that he noticed his thumbnail looked shiny, and upon further inspection the shininess wasn't rubbing off!
We were all amused at my dad's shiny thumbnail. I took pity on him later that day and removed the polish and all was right with the world.