If you would ever wonder what the difference is between Dutch and Flemish, than the difference in meaning of the word 'poepen' is a good example of the nuances that define Flemish vs. Dutch.
In the Netherlands : 'Ik moet poepen.' = I need to got to the toilet.'
In Flemish: 'Wil jij met mij poepen?' = 'Do you wanna have sex with me?'