tbh mid and older sisters are pretty dang easy to get the relationships for, the mother story i haven't touched yet though. want to get younger's before that
All relationships with the girls have to be initiated early in the game, because at a certain point it isn't possible to hook up with them. With Rachel it's a matter of getting her trust and corruption high enough and going with her on a date to the cinema.
tried turning down Ana and Alina, but no luck. i know how to get started with Rachel (kiss her, then spy on her in the bathroom.) but beyond that i'm stumped. lol
