We don't know that yet. Most people commenting here regarding the future relationship between other characters have been projecting their own thoughts, nothing that was actually confirmed at all.
Well I only said Eric/Vi was NTS, as far as I see it though you can't really have NTS or NTR with people you're not in a relationship with. Not that I really care, but they're allowed to have sex with who they please it's not cucking if your step sister or step mom sleeps with another guy behind your back (is that even behind your back? why would you even be expected to know?).
I think people should just enjoy the incredibly well put together scenes and sweat less about the little stuff. Enjoying the good vibes, music and art direction rather than being obsessed with "Oh my god how dare Eric sleep with this character" or "Oh my god MC is too much of a pushover" or what have you.
By the way, not arguing with you Cho just further elucidating my own thoughts.