mashiro/azuki have confided in each other a few timed before the iwase incident; before the relaese of trap, when mashiro and takagi were "split" and when azuki was dealing with the photobook thing, to name a few. The only problems between them during the Iwase incident was a misunderstanding: Mashiro didn't feel like it was his place to talk about Takagi's problems, Azuki took that as a lack of trust.
Either way, it really wasn't a "monumental" chapter for the two fo them imo, which was my point. I'd even say that since the hospital arc, nothing has really gone on between Mashiro/Azuki; this current arc has mainly been about Takagi/Kaya. Most noticibly in the last 3-4 chapters, between Takagi telling Iwase about his feelings for Kaya, the proposal, and most importantly (imo) his realization that he wants to succeed as a mangaka not for his original motives, but to provide a good life for Kaya. Which is why the current troubles with Tanto have been so rough on him, he knows he's over his head but he won't give up because of his feelings of duty to Kaya.