It appears to be during the world days as Russia and Germany are both wearing their repective uniforms. Russia comes up to Germany and wants to greet him with a kiss on the lips, on which Germany gladly refuses by slapping his hand over the other's mouth.
Russia soon lurks in the corner, complaining that Germany refusing his kiss has make him very sad, Germany tries to comfort him by saying that he could do any of his Russian greetings excepft for the kiss on the lips. Russia smiles shyly that he'll blow a kiss to him while fiddling with his fingers as Germany facepalm himself.
The two are often portrayed as "lonely", often looking for friendship of companionship of other nations. Quite a lot of fanworks include the two needing or enjoying the other's company.