Pain, all I know is PAIN

I believe it happens around ch 80 if I remember the comments correctly

I could tell if I had the raws, but ch 48 is chapters 102-105 of the novel, and the divorce is in ch 164 of the novel. However, the novel divides the chapters in 2, and each chapter of the manga covers at least one full chapter of the novel (that is, 2 chapters). So we have 30 chapters at most left according to my math. My bet is 20.

So about ch.90~100 for the divorce

Not quite. I just read the last chapter of the raws, which is chapter 65, and it ends in the middle of chapter 140, so following the same pattern, my projection is around chapter 76.