To always invade the territory of or make yourself known in any situation you can find. Someone who craves constant attention or believes they are the subject of every conversation or event.
From the idea of animals urinating to claim their territory. Notably, on other people's yards.
Joey, "That emo
kid is constantly craving attention. A few people were talking about love stories, and he starts complaining about abuse and suicide."
Trey, "Yeah. I know. He likes pissing on every yard."