The way to describe the behavior of a bi-polar lover. Traditionally used when a great date with said individual is followed by an extremely bad or awkward date.
Joel: hey how was your date last night, you were really excited?
Brian: horrible we had a great time last week but last night she spent the whole date texting.
Joel: she is a total hot fish cold fish... get out now.
A generic email from HR telling you that you have not received the job you applied for. It contains many of the same elements as a dear John letter. We like you very much, we appreciate that you like us as well, but their are other people that we more interested in seeing.
Joel: Have you heard about that job yet at the hospital?
Kobar: I woke up and found a dear john email in my in-box. Looks like I'll be bagging groceries for the rest of my life.