So is Charles Henri gay? Or not? Like he has so many homoerotic moments with the character...

I think he's at the very least bi and has a bad case of 18th century flavored comphet. One could argue it's bc french people are very open with physical display of affection and back in the day maybe kissing someone on the mouth was more casual but being french myself idk about that lol... If you recall he's never the instigator of both kisses. Jean and later Louis both kiss him and he looks surprised but not reticent. So while i hoped it meant he'd be "actively" non-straight to me it seems more like the author did that to show Charle's "profound friendship" w each boy in a mostly platonic sense (but not entirely i think... considering it was written by a 21st century guy who knows the implications of such scenes and still decided to draw them). Tbh the manga also has a few queer themes like the whole character of Marie-Josèphe who's obviously bi/pan, maybe non-binary and generally not giving any fucks, her (NOT platonic) relationship with Marie-Antoinette (bi or lesbian), the Chevalier d'Éon, who is i think a trans woman. Also the scene where Charles goes drag lol, and the way the only people we've seen him being friendly, affectionate with and attracted to were men (Jean, Robert, Louis and even the puppy crush on his uncle...). We don't really see women by his side except for sexual and reproductive roles (Jeanne to make him "a man", his implied flings, and his unimportant wife). All in all I think the author made his sexuality vague on purpose: while he seems genuinely attracted to men, he also isn't uninterested in women and still holds traditional religious and social values of family and gender roles of the 18th century and thus doesn't even question himself bc for him men = ~friends~ and women = sexual pleasure and family duty. So yeah, comphet. Also the way his relationship with men is portrayed reminds me of how mlm relationship used to be in earlier centuries in many cultures including japan, ancient greece, the whole thing with knights and Vikings too i think?) where two men could technically be in a more or less romantic relationship, it just wasn't overt and and didn't have the same status as a het relationship. Like sworn brothers typa shit ..... So yeah. The author is obviously very informed on this part of history so i think he did all that on purpose.

"Depending on the time of day, the French will go either way"

First reply makes sense and I came to think more, the second reply

Or French kiss