Either
a) there's a plot hole large enough to drive a thousand Futa cocks through
b) Elli's going to be fucking the entire town.
90 percent of the people living here are Futas.
So, all your classmates are in the same boat, and your teachers, all of them have been and will be around Elli even more than the MC's mother is. If Camilla wasn't sexually bent before Elli was born, living under the same roof with her would likely bring out all the perversions, and make her jealously tease the one boy in the village that has Elli's affection.
Every Futa who interacts with Elli on any regular basis is apparently going to need Elli to relieve their sexual desires.
Yet, it is the MC's intimate acts that ease Zoe's needs, not Elli's, and Zoe's complaint is that she's not supposed to masturbate rather than Elli's presence, which make me wonder if at some point we're going to find out that those quotes are bull and just a story Julia and Camilla used to cuckold the MC.
I wouldn't be surprised about Camilla doing that. It would be very fitting for Camilla's character as written so far. It would be very wrong for Julia's character as written so far.
Considering how new the current intro to the game is. I'd assume that it's potentially an oversight. There's a number of possibilities and ways to go about things. I could easily see Camilla lying to everyone involved to attempt to get her way, hoping and praying that revealing the MC as a perv, and getting her best friend involved in fucking her daughter be a gateway to opportunity for herself.. To that end, she'd probably make up whatever it is that she can to get her way.
I think it would be a more interesting approach if it was actually the MC that was driving Julia mad though. And Camilla basically was just trying to explain away her extreme lust in a way that more benefited her. Because after all, if Elli is capable of driving any Futa mad, it would be her Mom that would be far gone the most.. I can't imagine any scenario where this doesn't end up causing complications in the notion that there's no way Camilla wouldn't coerce her own daughter or try and manipulate and pervert her while growing up.. So in my current head canon at least.. The "Females drive Futas into Estrus" thing is BS.
I can't imagine Camilla denying her lust for so long, but I could definitely imagine Julia doing so.
There's already enough signs towards it that could be re-written easily to make it so.. Julia always going to bed with a massive erection.. That most of the girls at school seem to interact with you and not Elli (There's no way that they wouldn't try and date Elli themselves or stop throwing themselves at her daily). While yes, I can understand that the original plot may have wanted and desired for you to lose your girlfriend to lust (And I still think that should be a major option). Some of the logic being applied currently is a bit immersion breaking, but could easily be fixed in more fun ways than doing away with it altogether
I do agree with you that it's a bit of a plothole in other ways as well, because like you said.. She's been around your classmates a lot as well, but even still, it seems like most of them have a higher interest in you than her.. Or ignore her entirely (At least in the beginning). Which actually routes back to my original idea, it would be interesting to find out that it was instead the MC that was the trigger.
Maybe it's just me, I don't mind NTR of any variety, but I just think it stands to be a lot more fun and interesting with routes and paths for both the girlfriend and the MC to end up being corrupted.. And Vanilla NTR can be rather boring to me sometimes.. Not that this is vanilla, I'm just saying there's a lot more spices that can be added to this dish
