Volume 4 (up to Chapter 36) came out in English on the 12th. Here are some spoilers if anyone feels impatient waiting for new chapters. I'm curious about the thoughts of other people who have read the volume as well.
You could say that this volume has a lot of mood whiplash, though you could also argue that it's a smart way of showing how the characters are constantly torn between wanting to smooth things over and needing to be honest with each other, as you can see in this last chapter.
Saeko tries to keep herself busy as a way to put off spending time with Miwa. When she's finally unable to avoid her, Miwa tries to get her to talk about what's wrong, leading Saeko to angrily point out that Miwa is also trying to hide her emotions and still has feelings for her old crush. The two of them finally talk to each other honestly (kind of?), with Miwa admitting that her feelings for Shiho might have come back when she saw her again, though she didn't act on them. Saeko says that she's not angry and they won't break up, since Miwa chose her over Shiho. They start having sex again, but Saeko can tell that Miwa is forcing herself to say "I love you" and clearly still has feelings for Shiho. While they're in bed, Saeko suddenly says that they should break up.
After work, Saeko basically spills her guts to Yuria (female coworker), saying that she didn't feel loved by her partner. Later, Saeko and Miwa meet up to formalize their breakup and go back to being ordinary friends. Miwa still feels guilty and depressed, but starts to acknowledge that she didn't feel a deep, romantic love for Saeko. To their friends' confusion, they return to being friends pretty easily, at least on the surface. Rika easily convinces Miwa to message Shiho. Yuria mentions to a coworker that she has a girlfriend now.
There was also a very brief flashforward which I thought was unnecessary and slightly detracted from the mood, though I already knew what would happen since I've been keeping up with the raws (which have reached 70 chapters by now, so there's plenty more drama to look forward to).