I think it's a good general principle that the actions depicted in comedy manga should not be taken as a guidebook for optimal real-life behavior.
As opposed to dramas about highschool girls having affairs, you should learn everything about life from them :P
Or maybe not even then.
One of the characteristics of comedy manga series like this one is the piling up of one premise after another, some more plausible than others, until, if we were to actually stop and think about it, the whole thing becomes a completely preposterous house of cards teetering on the edge of madness.
But as manga readers we are accustomed to swallow each marginally possible premise in turn and so end up discussing the ethics of specific situations like “How would you feel if you came home and found your cram-school-teacher/lesbian-sex-worker partner demonstrating her pubic-hair grooming techniques to a young fellow student who aspires to the technical knowledge of a professional lesbian sex worker?”
Never stopping to think, “Wait, does Japan even have dedicated lesbian brothels/escort services? Does anywhere?”