This comic is only a mediocre fit here, but I thought it worth posting just for some cultural fun. It's originally a Danish comic called "Rasmus Klump."
This makes me think of some alleged trend in EU I read about several years ago. The idea was that high school boys would jerk off into their hand, carry it discreetly, and smack someone with it. I can't remember what it was called, and my only source is an article that I'll likely never find again, but yeah, that's what this comment reminds me of.