It was pretty obvious. Give MC a way to healthy outlet to express his desires to fuck the 3 younger girls just for it to blow up in his face and make him want to fuck his step daughter and 2 neighbors even more.
That was handled really poorly imo. I don't particularly care about choices in these games as i'm mostly in it for the porn, but the dev wasted an opportunity for an impactful choice there.
choice 1: fuck the prostitute - MC is satisfied, goes home and it takes a bit longer for the corruption
choice 2: don't fuck the prostitute: MC is not satisfied, goes into step-daughter's room and she wakes up for some naughtiness, which at this point would probably be like a hand job or mutual masturbation.
what we end up with is sex scene or no sex scene which is the most boring way to treat choices in these games.
It should be choice A - sex scene, choice B - different sex scene
All that being said there aren't a ton of decent games doing oyakodon so when there is a new one i'll take it where i can get it