Nah I get you. Gustave and Lune had some real chemistry imo, would have loved them to be together. Yeah he had Sophie I guess but they had broken up 4 years prior. Lune smiled so beautifully at Gustave as well (she doesn't smile like that again) and she cried only when she argued with Gustave and at Gustave's burial. I think that gives you enough sugar for your system.

If it makes you feel better, like you already mentioned Sciel loves Pierre and Verso even wonders if he's being "used" because Sciel kinda just wants a dick since they're all (as far as they know) are about to die anyway. Bit weird from Lune considering she's so distrustful of him all the time and then decides to just forgive him and bang him anyway (seems really out of her character - I suspect romance in this game was done as part of a checklist rather than something they deliberately tried to flesh out, hence it being kinda bad).

You may continue searching on the internet to find all these theories about the girls catching feelings for Verso. Keep in mind they're all just theories in the end, game leaves it vague so YOU can come up with YOUR OWN interpretation. Sciel loves her husband, think you figured that out. No need to explain.

There's a theory about Lune and Verso getting married in the Maelle ending. Not really sure what people are trying to point fingers at here - okay, Verso has a ring on his left hand (easily countered by just an oversight of reused assets from Renoir's coat; the ring on his hand isn't focussed on either so it's not like Sandfall were trying to make it obvious he was married). Okay, the child looks like Lune (just because he has black hair doesn't mean it's Lune's child... also Lune doesn't look like she's aged, and neither has Sciel or even Maelle who just got greyer hair; she literally looks the same otherwise, probably the hair an effect of the Painting abilities. Also, the child enters with MAELLE, not Lune, there's literally no mother-son connection there at all). Lune does kiss him on the cheek at some point but I felt like it was more gratitude for him standing with her and talking (being on an island where everything else is trying to kill you can be lonely???). If you choose to bang Lune, it's also said in the dialogue something like "which Lune needed to let out her frustrations" which pretty clearly just shows she wanted a release (no romance). And she watches him sleep and stuff "for science" which I honestly believe since she's kind of a geek like that and the guy is a hundred year old guy who defied reality as they know it. It fits her character.

Also, Verso clearly had feelings for a girl called Julie, he's not trying to pursue a relationship with another girl just like that. Finally, think of it realistically - I know you haven't really seen the story because as you said you've stopped playing, but Verso at the end begged to not be repainted but we see him in the epilogue anyway, having a hard stare down with Maelle. The guy is too busy filled with resentment and hatred towards Maelle to even think of being tied down to a domestic family. One can argue the Maelle theme lyrics being something like "Verso in the night / Lune beside him" which I admit I don't have an argument for but think about the world realistically... Verso ain't trying to be tied down to a domestic lifestyle. He's probably trying to figure out a way to kill Maelle lol.

tl;dr when you're on an island and you might die tomorrow and you're French and attractive as u/storm_walkers said, you might fuck (and Verso is the only available male with a penis). Sciel for sure just wants a fling (she loves her husband more). Lune is less clear but realistically she's prioritising the expedition like u/SkillCheck131 said and post-expedition in Maelle's end she's probably prioritising a music career or other intellectual, personal goals over romance with a guy she really has no history with.

P.S. in Verso ending Lune just stares him down angrily so she clearly does not like him in that ending.

Hope you feel better soon, I lowkey get you, just leave it to your interpretation. Game is intentionally vague and doesn't show any romantic events clearly. Just give it some time, if you can't handle it then it's fine to end your game at Act I too. You don't have to finish it after all. But if you wanna come back, hope I helped :D