Writing 126, via ShAmPi

Dancing Cirque Mistique
Aalst BELGIUM 9300
Men's restroom, 2nd floor

(Printed sign)

Drink met mate

Then in black marker n, geen liters bier maar vaten added, which makes:

Drink met maten, geen liters beer maar vaten

Translation:

Printed sign: Drink with ease
Added text: Drink with friends, not liters of beer but barrels