Despite the serious business of the day, Jean-Claude Juncker appeared to be in a jovial mood as he arrived at the weekly college meeting of the European Commission.
Mr Juncker was seen kissing colleagues on the head and playing with their hair.
The European Commission president was seen greeting EU Commission Chief spokesperson Margaritis Schinas by stroking his hair, forcing the official to grimace.
He then planted a kiss on the head of First Vice-President of European Commission Frans Timmermans and was seen laughing out loud before the meeting began.
The flamboyant behaviour is not unusual for the EU chief who has become known for kissing and slapping colleagues at high-level events.
Yesterday he appeared to kiss Portuguese member of European Parliament Maria Joao Rodrigues on the nose as the pair attended a forum in Brussels on the EU’s future before warmly embracing Tavi Roivas, the former prime minister of Estonia.
In 2014 the EU chief was caught in an awkward high five with then prime minister David Cameron.
Mr Juncker’s overly friendly behaviour comes amid a furious row with Theresa May ahead of Brexit negotiations.
The European Commission president sparked outrage when he said he would not give an EU speech in English adding “slowly but surely, English is losing importance in Europe”.
Leaks to a German newspaper over a working dinner at Downing Street saw tensions escalate with many accusing Mr Juncker or his chief of staff Martin Selmayr of being behind the story.
German magazine Der Spiegel reported that an angry Chancellor Angela Merkel was “sour” with Mr Juncker over the leak, which she felt had “heated up” the situation in an unhelpful way.