The King has vented his frustration at a leaky pen during a signing ceremony in Northern Ireland, the second time in recent days he has shown visible irritation during such proceedings.

The monarch, visiting Northern Ireland as part of a tour of Britain to lead mourning for his mother the Queen, was greeted by cheering crowds and welcoming speeches, before delivering his own pledge to the region.

Shortly after, when signing a visitors’ book in front of cameras at Hillsborough Castle near Belfast, the King reacted in frustration when a pen he was using leaked on his hand.

“Oh God I hate this [pen]!” he said, standing up and handing the pen to his wife and Queen Consort Camilla.

“Oh look, it’s going everywhere,” Camilla said as the King wiped his fingers.

“I can’t bear this bloody thing … every stinking time,” he said as he walked away.

Speaking before he was made king, one former aide told Reuters the then Prince of Wales could be fun but was also short-tempered and demanding.

On Saturday when signing documents in London, an irritated King gestured for aides to help when a pen holder on the table got in his way.

When completing the documents on Tuesday, he also used the wrong date before checking with an aide who told him it was September 13, not September 12.