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.
by Vincent84 October 5, 2009
Get the hot fish cold fish mug.