What’s The Grossest Thing Your Kid Has Licked?

I was thinking about this the other day when I was watching my nephew grab food and dirt on the floor and eat it. It was rather gross and I kept telling him to stop picking stuff up off the floor and eating it, but he wouldn't listen.

Recently, Halle Berry's daughter was caught licking the steel safety bar on a ride, but mom didn't seem bothered by it. 

We all know kids will be kids and I know I used to take things off the ground and eat them when I was little. Looking back it was rather gross but that's okay right! So what's the grossest thing your kid has licked?