If there wasn't the oneshot, I'd be thinking that somehow, the author would aim for them to solve their problems and stay a couple. But unfortunately, we already know that they can write the reverse.
So, the flags raised increasingly spell the doom of this relationship.
But then, at this point, I'm not sure it would be a bad end if they break up and find another more suitable partner. Because, they started to go out just because finding a partner is difficult for lesbians and they just happened to chance upon the other. But it doesn't mean they make the best couple ever, as exemplified by the recurrent miscommunication between the two.
So, maybe moving on from this relationship full of thorns is what would be best for both of them.