Arthur was an extremely spoiled child and Merlin had no-one else to blame but himself. People who had unlimited magic and inability to say no should have never taken care of children, especially ones as compelling as Arthur. Arthur needed only to pout adorably and Merlin found himself magicking maps of long lost pirate treasures at half past three in the morning or apparating in the middle of savannah because Arthur wanted to pet mongooses.
And it was best not to even think about what happened when Arthur had to resort to crying. The whole Europe was still recovering from the four-day snowpocalypse of last Christmas when Arthur had been convinced that Father Christmas could not deliver presents without snow.
It had started with Merlin's first big mistake: letting Arthur watch television, snuggled in Merlin's lap, Cavall (Arthur's plush platypus) tucked between them and Arthur sleepily sucking his thumb. Arthur was finally content and the tears were drying as the television showed the same view as the windows; big white snowflakes quickly covering the whole land in white. The news coverage on the sudden, heavy snowfall affecting the Christmas celebrations of the whole of Britain was just ending when Merlin committed his second mistake: he did not turn off the television before the news switched to Italy's upcoming elections.
On screen, several old men were walking to their black cars. Arthur stopped sucking his thumb.
"Merlin, where's Italy? Don't children wait for Father Christmas there?" Arthur asked, brows furrowed in confusion, and Merlin realized with a mounting horror that a) Italy was not covered with snow and b) Italy was not yet covered with snow.
In hindsight, maybe showing Italy from the big map of Europe was not one of Merlin's finest moments, but at least he didn't use the ancient globe from the library or the meteorologists would have had ulcers for the next century.