"Lemons are stories that explicitly depict sexual activities, so named because they leave a sour taste in one's mouth, if not other places. A lime is a lemon with most of the really good bits taken out."
— Gary Kleppe, "A Guide to Writing Really, Really Good Fanfiction."
"A Lemon-fic doesn't need to be vulgar. It just needs to make you check your parents aren't in the house. And a good Lemon-fic just needs to make you want to read the next chapter. Except, one-handed."
"Now I know why they call 'em lemons. They leave a sour taste in my mouth."
— from Anime Detective: Crossover Crisis, by Pearson "Doc" Mui.
Kasumi: Would you like something from the fruit bowl to finish with?
Kentaro: Sure! Let's see, you've got oranges, apples, grapes... is this a lemon?
Kasumi: Goodness, no. Just an ordinary fanfic.
— Kasumi Tendo dents the Fourth Wall in There Goes The Neighborhood, by Gary Kleppe
Have sex, that's what they do. Knock boots, bumb uglies, grind genitals. Maybe they solve a crime, maybe they write an article for the Daily Planet, but the important thing is they screw like bunnies.
— The Clark Kent and Chloe Sullivan Mysteries'' by Firebunny