Alright then. Here are some kinks that would fit well for the narrative:
Anal, rough sex, spanking, creampies, facials, oyakodon (mother and daughter)
As for the setting, it can be in a suburban area we could have Lucifer and Judgement be neighbors towards the mother and daughter, leading to some conversations, drinks and gradually leading into some hot, horny fun.
References for Lucifer, Judgement and the two OCs can be found below.
Again, as stated earlier, Lucifer greets her neighbors, has some conversation, getting to know them, stuff like that. Then Judgement arrives and joins in, albeit reluctantly, but warms up to the mother and daughter. In fact, the daughter shares the High Prosecutor's love for small animals too, so that can be a good conversation starter.