Fetish Fuel is a fan term used as a label for any element of a story that serves to titillate the reader's erotic or obsessional sensibilities.
The term is not limited strictly to what your dictionary would define as a fetish, but it excludes Explicit Content. It stands in pretty well for the word 'fixation', actually. Both of these sentences mean the same thing:
- "He has a Light Saber fixation."
- "Light Sabers are his fetish fuel."
We no longer collect examples of fetish fuel. We did so for long enough to establish that literally everything is someone's fetish fuel, and that some individuals are quite willing to go on about theirs at length. The topic seems to want to get out of Family Friendly territory too easily for TV Tropes.