I don't think Chief/Cortana ever had a romantic relationship, Chief at the very least never displayed such a thing, I'd say their relationship was more a family one, Chief definitely loved her but I don't think it was romantically. Course he was distraught by her death but by that point he had lost a lot of close friends, he had spent years with Cortana and they went through hell together, they are partners but not in a romantic sense and Chief is a little lost without his partner due to how much he relied on her in those years, she basically lived in his head, Lol.
Halo 4 was all about Chief opening up and showing emotion, so that was directed towards him losing Cortana, Chief also doesn't like failing, as evident by Infinite where he takes his loss against Atriox badly and blames himself, he literally watched Cortana die before his very eyes and likely believed he failed her, it wasn't a problem he could fix, he could do nothing about it.
Cortana I could see an argument for having romantic feelings for Chief but I still don't see it, I also would point out that Cortana is based off Halsey's brain, Halsey and Chief have a mother/son relationship so it makes the Cortana romance a bit weird, Lol.
Cortana's death really made him open up but I think he would have a similar reaction if say, Kelly or Linda died, Chief does have emotions, at least in the books, Lol, he was pretty distraught when Samuel died for example.
I'm also not sure if John is capable of romantic love Tbh, UNSC have screwed him up, the only time in his life he had romantic love was as a child, then he was kidnapped and turned into a killing machine, Lol. I sadly don't think John will ever settle down, that just ain't who he is, there's always people to protect, you can see that he genuinely wants to protect Humanity, I think his future is dying in battle.
If there was a romantic interest for John, I think it should be Kelly, she knows him best, she has known him the longest, she is his closest friend and his most trusted ally, also the only person that John has ever described as being beautiful, Lol, but I think again nothing romantic will happen between them, also 343 needs to actually use Blue Team effectively in the games and show their relationship of first.Last edited by Ryuu96 - on 16 December 2021