I also learned in an awkward way that waving my hand next to my cheek isn't an international sign for lekker. I moved to Canada about 20 years ago, and still sometimes do it, but apparently here it means you're signaling that someone is a little bit crazy.

Are you sure you are not licking your fingers?

https://www.learndutch.org/beginners/expats-about-nasty-expe...

https://www.reddit.com/r/Netherlands/comments/14kn2ei/i_thin...

https://dutchreview.com/culture/gross-things-dutch-people-do...

Now I wonder if mixed Italian-Dutch children have two different forms of communication by gestures. Would be interesting, especially since neither are true sign languages.

Eating only half a pepernoot and putting it back in the bowl is crazy behavior.

In this case the gesture is to not speak with a mouth full of food, which is understandable.

Needs the sound! Otherwise, even other Dutch people will look crazy at you. :)