aw, don't be sad. Your head-canon is all that matters. When you play, they will never touch another guy, right?
It's not that. It's just that:
1) Sharing Jenny or even Emily with some random asshole, apart from being disgusting
![Kappa :Kappa: :Kappa:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
, makes no sense at all to me. Alex is getting more slutty, so on a certain path she could easily be talked into doing that by her corrupted bestie. But Jenny and Emily would be stupid IMHO, just kink for kink's sake.
2) The sharing options with those girls means more dev time devoted to those scenes, what equals less time devoted to these girls in the scenes that I will enjoy. After so much time waiting for anything relevant to happen with them it's still more discouraging to know that eventually the occasions I will have to enjoy them will be few and far between. I mean, if TTrick was a 4-guy team providing extensive content every 3 months I wouldn't mind at all because every few months everyone, me included, would have some substantial content that they'd enjoy.