Pope Francis is quite used to unscheduled encounters in his travels and usually takes them in his stride.
But it's not very often that someone tries to take a bite out of him.
Just to be clear, though, this wasn't on the level of footballer Luis Suarez, known for his habit of chomping down in the heat of the moment. Little Karl Klapper, from Ludenscheid in Germany, is only seven months old, and when introduced to the pope by his parents Jan and Kirsten did what any teething child might do – took the hand of the most powerful man in Christendom and put it in his mouth.
Dad Jan said: 'The Holy Father made light of it. He wanted to know how old our little one was and what he was called. He was a really nice man.'
German media are dubbing the incident the 'nibble attack'.
It's not the first time children have brought out the softer side of the pope. In 2013 a boy wandered on stage as Francis addressed crowds of thousands, resisting efforts by the assembled cardinals to remove him.
And in 2015 he burst out laughing during a visit to Philadelphia when someone pointed out a little baby dressed exactly like him, in papal robes and a mitre.