This keeps happening! I take my clean presentable child somewhere, I get to the somewhere, take him in, look down after awhile and see that he is mysteriously smeared in filth.
I'm fairly certain he went into a hospital with me like this today.
(No, your monitor isn't dirty. There's silty grey stuff all over his face)
The other day I took him into Payless shoes, and after a good 5 minutes I glance at him and he has a black smeared hand print running down his entire face. I'd just been standing there all nonchalant while people stared at my grime covered kid. He looked like a Native American warrior, or a street urchin.
"Oh, don't worry folks. I just found him on the corner and thought I'd take him home, scrub him up, and pass him off as my own for the next 20 years or so. Then I can tell him about his past and the trauma of the incident will inspire him to become a great novelist and I can live off of his royalties for the rest of my life."
What were we talking about? Oh right. I was mortified. Plus, I didn't have any wipes with me so I was pulling his t-shirt up practically over his head in order to wipe his face off. Classy Mother of the Year right here.
After some serious bewilderment and detective work, I've hypothesized that he's running his hands along cars in parking lots while we're walking into places. Then, when he touches his face the grime from the cars gets transferred. That, or he's pilfering coal from an unknown location and keeping it in his pockets to apply as war paint in order to intimidate all we encounter. Who knows.