LOL (Laughing Out Loud) Puns

I was ringing out a son and father at the register. I tell him his total is "seven forty seven" and the father replies "I didn't buy a plane!" and looks at his son to get a quick laugh, but his son wasn't having any of it. Meanwhile, I'm trying to hold my laughter because i know this is a typical dad joke. But that's not the best part.

He swipes his credit card and reads the credit card reader out loud, "Sign Below". He ends up writing "BELOW" as his signature and says out loud to me and his son "It told me to sign 'Below' and so I did". His son responds with "Dad you are so embarrassing" and I'm chuckling out loud cuz I've never seen anyone do that the 3 years I've worked there lol

TL;DR Dad writes "Below" as his signature because he took it literally as any days would.