To be clear, I DO NOT think MC and Jill are related. Not what I'm about to say. But...
It's weird that in a sex game, with so many girls you can do so much to already, the farthest we've gotten with Jill is an accidental boob grab. Depending on your choices MC has been in more asses than a proctologist, but with Jill it's like we're in 6th grade. I get that she's the chaste "good girl" option, and I'm all for that, but an actual lesbian has banged MC at this point. Second base seems reasonable by Episode 6.
My point in bringing this up is -- and again, I don't think the answer is incest -- I'm wondering if this isn't intentional. By which I mean, are we getting NOTHING off Jill for a reason other than because she's the "good girl"? I'm probably overthinking this, but it's starting to feel really conspicuous in the larger context of what is, let's not forget, a porn game.
See, I'm okay with this. The situation Sage is in, the place she's at emotionally, it would be unrealistic if we could swoop in and just fix it with a few words and a shag. She needs time and space to heal, and that's all MC can do for her right now. It hurts, yeah, but it's supposed to.
No, it always goes that way. However, she says she and her boyfriend break up and get together all the time, so if you ended that convo on good terms I wouldn't be surprised if she shows up again. And then leaves again. And then... you get it. I think that's the gag that's being set up.
I mean... maybe he pulls out? That makes it... slightly less vomit inducing. Maybe?
(Seriously though, if he is, and he's smiling like that while he does, that's like some serial killer shit right there.)
It's certainly possible (and far more palatable than the incest theories). Even if not, I think there's going to be something in Lynette's diary, at some point, that ties her to someone MC knows in the present. Not as a relative, but some kind of tie. It's the only real reason I can see for introducing the diaries in the first place.