I forgot most of the details but I remember that around the beginning the MC told a girl that his dream is to become a masseur(lie) and convinced her to help him by allowing him to practice his massage techniques on her, which get lewder and lewder overtime. I didn't read too far into it but it was fairly highly rated and most of the reviews about it talk about how the MC is actually a good guy when seen from an objective point of view and that the MC's POV is actually biased against himself, making him look like complete scum.
ive been scouring the internet for the past like 3 hours trying to find this exact novel, you are a godsend