Treading in black waters means you are fighting or argueing with someone and you are JUST on the verge of telling them to fuck off. You can only use this term when you are about to end an arguement or a friendship/agreement. Should be used if you are completley ready to lose this persons trust and affection.
After James starting being a smartass and splitting hairs with me about how the server operated, I warned him he was treading in black waters.
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.