From a casual reskim, I think the idea is that while Takako's very much a sexhound, Kuyou's the first girl she's actually gone dokidoki for outside of sexytimes. Also this seems to pretty much confirm all the character side blurbs are canon (the post threesome ManaTaka interactions are mentioned in ch15).
I think most of us just accept that this is totally dumb and just enjoy it for what it is.