That never happened. The Germans and the Finns were allies through most of the war, and when they did fight in 1944 (because as a condition of peace with Russia, the Finns had to chase out the Germans), it was in the far north, a long way from Helsinki.
Maybe it was Copenhagen where they saw the fountain
(?), I’d have to ask again. My uncle has Finnish ancestry, most of the stories are about Finland. They went to a big car show in Germany while they were there, he has a couple Borgward cars he’s restored.