
From what I understand, Marius has a crush, and Mc hasn't noticed because she doesn't see him as an adult. I think Silvio is supposed to be the love interest, but his personality needs a character like Marius to be the go-between. I don't like it too much myself since Marius is underaged, but if he was of age, then he would be competition for Silvio. Analyzing this way makes reading less fun for me, but I hope it helps.

I need to say, it probably has this ship Marius x MC. Especially on the cover of volume 6 ╮( ̄▽ ̄)╭ I saw MC and Marius holding hand, so I assumed it probably swings to that ship as Silvio might be thinking of Marius as his brother-like figure (Marius looks similar to his late teammate). Thus, probably wouldn't try on MC route
Tbh the casual shipping between Marius and the MC make me uncomfortable. He's a minor and the age gap is huge. She also acts more like a big sister to him than a lover. She hasn't expressed interest but the backgrounds and mood around them makes it seem romantic which is kinda weird.