@spurgleburgle It isn't directly hinted at until page 4 with the whole "don't smoke" line while Sawako held her stomach. The whole chapter is really subtle and contextual, so hopefully that's on the author and not me...
@GaoMuscle Alhazred23 is correct. It also kind of ties into Nona previously referring to the situation as Haruto "letting himself loose on a business trip," which is apparently another salaryman cliche.
Just in case anyone asks "Why does Vernois not know that Nona is married to Haruto when Nona literally calls him her husband in chapter 11?" (and probably other places that I forgot) it ends up that I flubbed the translation a bit because I didn't look far enough ahead. Nona refers to Haruto as...
@lightningcloud You can rest easy, because this one is a little shorter. Well, there's also a sequel series, but Mai's Dad plays a much smaller role in that so it's quite different.
@superdoofus The order of the dialogue is Darling, Miyoko, Miyoko, Darling, Miyoko. It's a further allusion to what was brought up at the end of chapter 14.