The manga still wants to keep it as a thing he feels obligated to do or else for the sake of this sort of fan service instead of just letting him be able to refuse because he knows she won't do it after all the shit that made it obvious she probably won't do it
It isn't that weird for someone to learn how to get a reaction they perceive as positive due to not really understanding exactly what they are doing and to keep on doing it despite it being really bad. After a while, people give up and just ignore them instead of trying to explain the problem to...