I must say i was rather confused from the walkthrought. i mean bunch of choices and variables but what is which path and what that path does? its possible that i miss something but dont sure.
There are basically two main routes, the pivotal choice being #47 in the walktrough
* Sandra (&Haley) route: basically, if you chose to help Sandra with her clothes, she'll stick with you till the end, and it will cut out every other non-Haley romances (no possibility to even see anything with Alanna, Haley imposes you to stop anything with Diane, asks you repeatedly to stop anything sexual with Adrianna. Just Lisa remains, but nothing has really happen between you two -yet). In this route, Sandra will come at every week end at home event - excepted the very first one -, which will remove three sex scenes with Haley (second sex act in your in your child bedroom on the second week end (replaced by bj by Sandra), the cunnilingus the week after (replaced by sex scene with Sandra in the bathroom), and the one in the cabin on the last day of version 0.85). The story will also be more focused on how Haley is trying to include Sandra in your relationship (or how she becomes included in your relationship with Sandra...)
* The Haley-only (or sort of) route: chose to no help Sandra with her clothes at #47. The will remove the second sex scene with Sandra in the store, and after that she will completely disappear from the game (just a final appearance for the break up scene). This will, on the other hand, open possibilities with Alanna, if you have played squash with her (dancing is not necessary I believe) - one sex scene, and you see (just see) her again during Haley's appointment with therapist -, Haley doesn't impose you to break up your (potential) relation with Diane (and don't repeatedly tell you to cut the crap with Adrianna). There is also a scene (after the second week-end back home) with Lisa and her boyfriend in a dance club, where she reveals she suggested you to her boyfriend when he proposed a threesome MMF. And the story will be totally Haley-centered thereafter.