A phrase used often in the canceled TV show "Arrested Development". The phrase is mostly used when the characters talk to themselves after a serious of poor choices/bad events. It's used to make light of bad situations, although the characters themselves don't find it funny.
MARTA: "I was really worried about you"
GOB: "You've got nothing to worry about. We're going to be together for a long time"
MARTA: "We're family now - I'm so happy. I'm going to call the kids!"
<MARTA walks out of room>
GOB: I've made a HUGE mistake
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.