A big deal; important. Something everyone should know, and that - by default - one should assume all others know.
Person 1: Do you know whether Bella and Sash are still dating?
Person 2: I didn't know they were together at all. I thought Sash was gay.
Person 1: Of course they were dating! Their relationship was really big zimmers.
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.