In Roleplaying Games (RPGs), to become attached to your player character(PC) to an unhealthy extreme. The phrase refers to a line from the 1984 film "Mazes and Monsters". In the film, Tom Hanks' character's PC is killed during an RPG game, causing him to have a severe emotional breakdown, and eventually wail "There'sblood on my knife!" at the film's climax.
Someone who jumps from one relationship immediately into another one.
Serial monogamists can not stand to be alone and often suffer from vast commitment and insecurity issues.
Because they jump into relationships immediately after the previous one has ended, serial monogamists typically don't take the time to reflect on their behavior or why their previous relationships failed; thus, they end up making the same relationship mistakes over and over again.
Person 1: Damn, Dustin already has a new girlfriend?! It's only been two weeks since he broke up with his fiance! I think he's a sociopath.