Hermione chuckled, "Before his disappearance and her incarceration, Bellatrix and Lord Voldemort were lovers. When Voldemort declined to offer for her, the Blacks married her to Rodolphus. They've always disliked one another, so he didn't much care where she spent most of her nights. The Lestranges added a clause that they could divorce as soon as Bellatrix produces an heir, or at least they can go their separate ways."