A word I've liked ever since hearing it in the mid-1990s is this:
flutterlustation: the feeling one has upon meeting a particularly attractive member of the opposite sex. Not quite love at first sight but definitely chemistry at work.
I assume one could then also have the term flutterlust as a noun.
Origin: it's too long ago to provide a name, but the one and only time I ever saw it used other than in some of my own work since (I write for a newspaper in Canada) was on an early discussion group on the Internet dedicated for use by aspiring writers. A woman there used it and claimed to have coined it, which I had no problem believing in the context of the group discussion occurring. This would have been circa 1995-97. My recollection is it was a woman living in a southern U.S. State, possibly Texas.