If the point of the sign was simply to abstract the thought of "please stop eating my yogurt" then you needn't put any thought into it at all and leave the default font of Times New Roman. What they've done is actively choose to use another font for some reason.

If it is unimportant which font we use most of the time then why have you set the font family in your website? What made you choose Georgia over Comic Sans?

Fonts and typefaces are important, and Comic Sans is misused frequently.