I like the description about days spent by the inklab, because it tells us that the relationship between Chinami and Yukako has always been rather formless and abstract, focused more around simply being rather than pursuing anything or looking for romantic goals. In that sense, you could say it's less driven than a conventional marriage with 'objectives' of cohabitation and childhood, but as Yukako is starting to realize, that comfortable, companionable warmth might be precisely what she wanted her entire life. This isn't a steamy kind of affair- it's an attempt to reconnect, and find some semblance of satisfaction.
Chinami going on the offensive is great to see, because she's done playing the patient, invisible lover. She realizes that the their relationship only really became intimate once she took charge back when they were teenagers, and understands that she needs to do so again, because Yukako isn't strong enough. She'll invite Chinami in, let her get a foot in the door, but that's pretty much it- the rest is up to Chinami and her confidence. At last, we're approaching equivalency, as both parties to the affair reveal and seize their true desires.
Also, Dickey Spouse getting an SSR made me chuckle, because depressed salarymen seeking happiness in gacha waifus is quite realistic. If nothing else, he's used up all his luck for a while.