@TitanAnteus I think she explained it earlier but I'll spoiler it anyway,
she's got a Succubus-like curse on her that will syphon life energy from her and anyone near her, so she'd fucked people non-stop to use their life energy to negate the drain for now. Since Cliff proposed to her she's stopped banging everyone else and is focusing 100% on him out of romantic loyalty.
@TitanAnteus
Well, one could argue that they could've had better developed personalities if they were posed as heroines.
That said, I generally really like catgirls and doggirls, so that's where i'm coming from