Kaiser Wilhelm II sat across from Ferdinand I who in 1915 was the current King of Bulgaria. The two men had rather stern expressions on their faces, as neither wished to say a word about their current predicament. Nor their ongoing disagreements.
Truth of the matter be told; Ferdinand was favorable to the Central Powers from the moment the war began. But he did not immediately act to get involved. Now, however, Greece had entered the war on behalf of the Central Powers, and the two nations were feuding over disputed territories such as that in Macedonia and Eastern Thrace.
In fact, one might say this was an irreconcilable grudge. One that made the King of Bulgaria wish to go to war, but he had already recently lost a war pressing these claims, and if truth be told, he hated the Ottomans far more than he did the Greeks.