Not sure if that was an intentional outcome but I remember Sou stating that he understands what's going on at some level but stop himself from fully realizing it/acting on it, fearing he would turn into the unlikable asshole of the 18+ version. There's a line he doesn't want to cross, especially with his family.In other words, he's actually just as deluded as the rest of the cast.
Plus, considering his thoughts about Maria, he's a very pure Boi who highly regard women and would isolate himself if they turned out to be superhorny freaks. Which they unfortunately are in this universe.
Can't believe I gave this kind of thoughts to a stupid gag manga, but this one be compelling.