Well, come on, lets face it, if he actually wrote seperate plots for all of the various combinations of choosing and not choosing girls we'd never get any updates because the cast is too large.
I mean seriously every conversation would have to include 47 various options for who you had chosen to do what with and each group setting (eating, sleeping, watching TV) would require multiple render options depending on who you chose and who you didn't.
Even if the group was only 5 girls, there would have to be options a) Jamie, Shauna, Stacy, Liz, & Nat; b) Jamie & Shauna only; c) Jamie, Shauna, Stacy, & Liz; d) Jamie, Shauna, Stacy, & Nat; e) Jamie, Shauna, Liz, & Nat; f) Jamie, Shauna, & Stacy; g) Jamie, Shauna, & Liz; h) Jamie, Shauna, & Nat. and that's actually less complicated than it would be if there was a scene that included two girls other than Jamie and Shauna!
So every scene would need to have so many versions of it to accomidate all of the various choices, it's crazy.
Its easier to just ignore the choice that the player made and still render the girls into the scene and just not inclued their specific sex scenes if they wern't chosen but not change any of the other dialogue.