I'm actually rather less interested in how intimate they get than in the mother's characterization--we recall that Kageko's mom was practically handing out flavored lube during the sleepover at their house, so I'm wondering if we're going to get another maternal wingwoman or not.
I'd be more than happy if they do some lewd stuff together, but I'm more intrigued about how they are getting interrupted. Kinda hope Sakurako's rival reveals herself by appearing from under the couch.
Sure, they're going to get interrupted, but it's nice to believe that Tatsubon will illustrate 8-12 chapters of them making savage animal love to one another.
Count me in as another interested in seeing Mrs. Nikaidou's characterization.