Relationship Tag question

I'm not a newbie to AO3 so it's kinda strange to ask about relationship tags. I have only written specifically for a pairing in a fic, and I would tag them with "/" and with "&", for example A/B, then also A&B.

The problem is now I'm writing a story where A and B used to date, are no longer together but emotionally entangled still. B has started dating C and at this point is about to get married with C.

The emotional spine of the story is still between A and B (no cheating) and just in a few chapters I will break B and C up.

There have been some readers commenting about how they were confused by the tag because so far B is in a relationship with C since the first chapter.

My relationship tags at the moment are like this:

A/B, A&B, B&C.

The readers demanded me to add B/C tag in. I have my own rule to not follow any demand, especially with this particular story. And I thought if I added B/C, the readers who specifically look for this tag will come across this story and they will feel fooled by the tas since the story is clearly about A and B.

Am I doing it correctly or should I consider adding B/C?