I love these two and their dynamic - and also how their relationship has grown! They definitely have (and continue) to butt heads, but I appreciate that they still help each other out when it's needed.
@miyako19 I can't say I'd be a great fan of any random, regular words gaining a new, secondary lewd meaning, which becomes widely recognised. It prevents using those words in normal communication, eventually, thus making the language poorer. The only thing it grants in return are dirty jokes that you can use once in a blue moon.
@blanche I agree, just as Kiyo character wouldn't make a good maiko, Riko personality kind of clashes with the personality displayed by the other girls becoming maiko. But then again, the author only shows how riko interact with glasses-san while with kiyo or momohana mostly inner monologue.