Elaboration:

• Flavor Combination:

  The most common meaning of "lemon lime" is simply a flavor profile that blends the tartness of lemon and the zesty, sour taste of lime. This is often seen in drinks, candies, and other food products. 

• Fan Fiction Context:

  In the world of fanfiction, particularly in the realm of explicit content, "lemon" is often used to denote a story containing graphic sexual situations, while "lime" suggests a story with sexual content but less graphic than "lemon". 

• Other Uses:

  The term might also be used in a metaphorical sense, but it's less common than the flavor or fan fiction interpretations.