I still think that Bella is the mistress.One of the best games I played. Even if the end is for soon, i like having saves for lots of expected ending (Katie, Jenna, Monica, Debbie&Lily, Katie&Debbie&Lily, Debbie, Lily, Bella, Angel, Jolina, even Wanda ....)
I think dad's mistress will be Tereza.
Jolina may be a spy to tell lawyer if MC stay at Monica (she needs money) or maybe sh'es the mistress.
It's hard to tell if Elaine is good ot not. Bella could also be the bad (but very hot) girl helping his sister to get the money.