I just think if anyone in the world of characters was going to freak out about kissing someone for the first time, it'd be Marius, and he might be dramatic enough to accidentally rant about it in front of Courfeyrac, who might just offer, as A FRIEND, to help him practice, because he knows how to kiss girls very well --
--cue Marius judging him, and Courfeyrac laughing at his judgement, and taking him by the waist, and telling him: "you won't win her over by staring at her like that; now pretend i'm your lovely demoiselle, Monsieur Pontmercy." Marius, stiff and blushing and wide eyed, Courfeyrac, softening his own gaze, tilting his chin. Marius, feeling a little odd and a little hot under his collar, because he's thinkng of kissing Cosette but he's also thinking he's about to kiss Courfeyrac, and it's his first kiss, and shouldn't he have his first kiss with Cosette, but he does really want to be able to kiss her as she should be, and Courfeyrac offered, and the thought of kissing Courfeyrac is -- well, it's like everything else with Courfeyrac. It's easy to think of. It's easy to lean in, in fact, so easy to brush his lips against his, so easy to go a little further when Courfeyrac sighs against his mouth, and it's so easy than five minutes later they both have to take a step back and pretend like they aren't breathless and flushed and warm,,
and Courfeyrac says "Well, you'll make her very happy, of that I can assure you. Don't forget I need to meet her, one day, your beautiful lover."
"When we get married," Marius says, a little faint
"A kiss won't assure you marriage, my dear friend, do be careful," Courfeyrac laughs; its just a shade of odd, for a Courfeyrac laughter, but Marius says: "But I will marry her." and Courfeyrac's eyes are serious and fond when he says: "Oh, I don't doubt it. She'd be a fool not to, and you said she wasn't."
And if Marius' cheeks are pink; and if he says: "You'll be there too" a little impulsively, a little demanding, and Courfeyrac says "Obviously I'll be there" and they don't quite know what this means, but Courfeyrac pecks his lips one last time, and Marius' eyes stay close just a second too long, so he doesn't see! he doesn't see how much his best friend is pining, so horribly in love with Marius whilst knowing Marius has no clue and no intention to be in love with anyone else than his mysterious future wife, so freaking loud Enjolras and Combeferre's "sad courfeyrac"'s radar is pining on the other side of Paris.
and if marius thinks of it, later. and if marius is a little angry, and a little sad, years after his wedding, because courfeyrac said he'd be here, and he wasn't. he wasn't.