Should I Be Concerned That My Two Sons Haven’t Mentioned Their Toilet Paper Roll is Empty in the Past 5 Days?

I saw something interesting as I was trying to forge a way into my sons' bathroom at home today.  I saw an empty toilet paper roll on the dispenser.  This is greatly concerning because the boys never use mom and dad's bathroom.  That means they're either constipated or reeeeeeeaaaaaaallllllllyyyyyy dirty.

After searching for a rogue roll of TP somewhere on the ground or the side of the tub, I came to the conclusion that there was nada in that bathroom other than dirty clothes. I didn't find any DNA evidence on the dirty clothes.  How could they be using the bathroom with nary a roll of TP to be found? What's one to do?

I can't tell my wife because she'll freak out (she's not the potty-humor-loving wife you see in the sitcoms).  I don't want to force anyone to lie to avoid being labeled as gross.  I could just replace the roll of TP and act like it never happened.  Let's do that last one.

Fortunately, I've been working quite a bit the past few days, so my interaction with the "Dirty Hands Gang" was minimal.  And just for the record, I was in their bathroom for #1.  I didn't find out the TP was missing after sitting for business.