Get Sasha to 51 lp as soon as possible (pre 21st day, I believe). So, you need to do the three events to raise the max LP. Which are unpacking (go to the hallway when she's in her room), When you get her to 20 go to the pub. When you get her to 30 you'll get an event in the evenings. Afterwards, just meet her ,compliment her, talk to her and call her so you get to 51 as soon as possible, otherwise she might do stuff with her ex. You can alternatively get her Dom or Sub points above 25 (either way is fine).
Aletta is tricky, someone else will need to weigh on that (haven't finished the office harem yet).
Lexi's plot is literally getting her out of pimping... if you meet her autumn or early winter you can get to her storyline without having sex with her... in said story you get rid of her pimp. Then, when she's yours, just refuse other people's attempts to get into her pants (they'll pay you if you do).
Bree only gets with Dwayne if she's your slave and you force her to.
If Palla's sub is high enough you can tell her you are her only boyfriend and she'll agree. Although she say she wants to have her options and freedom open, she never really says if she actually has anyone else (by her story, probably not).
Finally, the NTR queen, Alexis. Have good fitness and charm, have above 7 energy and tell her not to see other guys, cheat or flirt with others. She'll say okay and that's the end of NTR.
