[i]In Roleplaying, a "That Guy"/"That Girl" is an annoying person that creates drama and ruins the mood in every way possible. Either by trying to force down something they like on a play (usually a trait, narrative tropes or fetishes), always using overpowered characters and trying to bring the stories to whatever he/she/(insert gender here) plans to do, or else having their muses have some knowledge that they should not have. 

In other words, they disconnect themselves with the roleplays they are doing for the sake of having their fantasies fulfilled. And they always believe they're right.[/i]

I couldn't find any thread with stories about these sorts of players, so I've decided to make one.