It's just an interesting theory. I don't think it's realizable at all, because otherwise MC would have to infect practical all the girls in the game and DPC would have to create renders of where he's sick and where he's healthy. Plus he's doing a lot of lewd scenes right now and that part of the game would suffer. Not having sex with Sandy is only because MC doesn't trust her, unlike Nicole who was seen in episode 3.
The whole scene in the hospital in episode 8 is like if MC cheats on Jill's way, he'll get infected and Jill will know right away. Neil tells MC to use protection several times, but MC ignores it and somehow that has to play out. This is classic Chekhovian shotgun.
It's still unclear how. If it's a girl's pregnancy as a result of cheating, there should be a situation where the protagonist has no choice where to cum. But on the other hand, that doesn't guarantee complete safety, and DPC can play on that. Or the protagonist will catch some disease and infect his girlfriend as a result of the affair.
