These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Considering the lack of attention from his girlfriend/fiance, it's not that much of a stretch to believe this.
Possibly because none of them have been actually "imprinted," the girls all seem to be developing emotionally. Yuria's development is of course the main storyline. However Juria seems to have developed a genuine liking for Yoshio, being more dere-dere than tsun-tsun around him and actually blushing a few times in later chapters. Even Yurin is acting more girlish and less totally-perverted-sexbot (well, "less perverted" being relative...), to the point of crying when a bunch of boys don't want to play with her and noticeably not using it as an excuse to grope Ippei when he comforts her.
Idiot Plot: Regardless of how many times Yuria tries to have sex with him against his will, Shunsuke never quite catches on that she might try again in the very near future and lets her continue to live with him.
Not to mention Akiba creating sex dolls with intelligence and emotions...
When he did create Yuria 1000, a dutch wife without any real intelligence nor emotions, it still was a huge failure as the newest creation just went around giving random guys handjobs, in public, with her onahole arm; the three Yuria sisters had to chase the reckless doll around and finally disable her.
The mangaka dropped a bomb on us on Chapter 56. Maria is revealed to not know anything about how a boy could cheat on her, but knows Shunsuke's cheating from just seeing the poses. It appears all her sexual knowledge of males just pertains to that erections = someone's doing something right. She doesn't even know what semen looks like and screamed that it was "strange juice" when she saw it her first time. While giving her fiancee a handjob. And not knowing that that could happen.
The Woobie: Yuria after she starts to be aware of her emotions. (Don't actually try to hug her though... See Covert Pervert above.)
Especially at the end of the island chapters where she feels like during the three days they were stranded, she managed to fail to help Shunsuke in just about every way possible. She recognizes and blames her Deus Sex Machina tendencies, and feels absolutely miserable. Verging on Tear Jerker because of a big Mood Whiplash for an otherwise absurd, comedic series.
Poor Louie. Between her own confusion about herself because of her budget-enforced "design issues" and the problems it is already causing for her, she is already on the fast-track to full woobie.