A/N: Let's start from what people really want to know: yeah, there's slash, mostly Enjolras/Combeferre, but aside from that, nothing more than you would find in canon. (Conversely, be ye also warned that some people are, gasp, straight. XD) These characters don't belong to me, clearly. This is not intended as an AU, since I have made any and all possible attempts to keep events from contradicting canon, although much has been added on to and slipped between canon events and characters, obviously. I would be pleased to hear feedback, but if you don't comment, I won't come kill you in your sleep, you can rest assured—and don't comment just to say, 'Eep, where'd the quotation marks go?' or 'What does "je t'aime" mean?' (The latter is the reason why they invented the internet—Google can answer your questions much faster than I can, my friends.) After all, I really did try not to use too much elitist Latin (or French, for that matter). I tried, really I did. But they don't call it the Latin Quarter for nothing. And besides, coming up with a declension for Enjolras's name for the title was just too much fun (I decided that it sounds best as a third declension, by the way, in case you're interested—enjolras, enjolratis, enjolrati, enjolratem, etc. XD). And since I am a responsible author, and since I very much like French and Latin in Les Mis fanfics but rather dislike the idea of authorial snobbery, I'll gloss the foreign-ness for anyone who's curious (dear God, fanfics with glossaries, what will they think of next?):
Mamour: Courfeyrac's preferred choice of condescending nicknames—it's really just literally an abbreviation of "mon amour," popping up from time to time in Molière and such. Likewise, Combeferre's more neutral equivalent, mami, is an abbreviation of "mon ami."
Mon vieux: another Courfeyrac favorite, but I believe he actually uses this one in the book, and if he doesn't, he should have. So there, V. Hugo. XD It means "old man," in the British sense, as in "buddy" or "homie," or whatever you prefer—a common address between male friends, even in modern French.
Mon cher: "my dear."
Miserere nobis: Church Latin for "Have mercy on us."
Oh là: a strange little interjection, an expression of dismay, difficult to translate. Perhaps equivalent to something like "Whoa," "Uh oh," "Oh no," etc.
Parbleu: "By Heaven!" Interjection. Nothing too special there...it just sounds less cheesy than sacré bleu.
Pardieu: Similar to parbleu, except it's "By God."
Ma foi: an exclamation without a real literal sense, but meaning, "Faith!" in the Shakespearean sense.
Grisettes: "the grey ladies." The lump name conceived specifically for seamstresses, because of the grey dresses they apparently tended to wear in Les Mis days. They are nearly their own archetype in 19th century literature, often showing up (even in Les Mis, I believe—see the part when Fantine is with Tholomyès) as the mistresses of students.
Je t'aime: I should not have to gloss this, but I will because I'm anal. "I love you," of course. As a historical aside, it should probably have been Je vous aime instead, since that tended to be the way lovers addressed each other in rather antiquated French; however, that rule is probably antiquated even by the Les Mis time period, and besides which, Combeferre and Enjolras always address each other as "tu" in the book (all the students do, if I recall correctly), so I stuck with that.
Te amo: The Latin equivalent of Je t'aime. Simply put, Te amabam is the past tense version of Te amo, and Te amabo is the future tense version.
Puerum flavum: Latin for "blond boy," in the accusative case, as Combeferre so delicately points out in retrospect.
Salaud: I believe this is in there somewhere, probably just because I like it as a word. It just means "bastard," basically, and sounds lovely when French people spit it out. Almost as musical a word as putain is. XD