I believe the Waloons (French)
Why don't the Flemish secede and join the Dutch?
Belgium is a construct of European power politics dating back to the Napoleonic wars. If the Flemish were to break away there is a deep seated fear that those wars would reoccur.
The national emblem of the Flemish used to be the Stars and Bars
So you can imagine their attitude to the subject.
My mother in law was 16 when the Nazi's came in and occupied her 16th century Flemish town. She tells stories about saving up her sugar ration to dump it into the gas tanks of German vehicles.
She used to be worried because the Germans were overdue for invading Belgium. She's now figured out that the EU is the way they (and the French) are invading this time. Her only hope is that the cretinous Belgian bureaucrats will screw up the EU as badly as they've screwed up Belgium, the whole thing will fall apart and they can go back to governing the town and the immediate surrounding countryside and be left alone.