from what i have gathered lemon is a romantic kind of story.  But then
some lemons have sex parts in them.  does lemon mean both romantic and
sexual?

Lemons are fanfics that have sex. Pure and simple. Limes have a hint of
sex, but not a detailed or semi detailed description of the actual act.
It would be more like: "But damn was she good last night," grinned
Ranma.

That would qualify as a lime quote because it suggested what they did,
but it wouldn't be lemon because it wasn't a scene with them actually
doing it.

The name lemon came from a show called LemonPie or something of that
nature... An older anime where every character was trying to get laid
with every other character (of the opposite sex, I would assume for an
older one...). Fitting title, then, ne? Not to mention some lemons can
leave a sour taste in your mouth... ;)

Hope this helps.

Mark Eymer