Brother's Betrayal

Bellatrix is deeply in love with Rabastan Lestrange, but she's engaged to Rodolphus, his brother, whilst Rabastan begs to be her one and only, Druella and Cygnus III have arranged her marriage and there's no stopping it. So what happens when the truth comes out and Bellatrix is about to be cut off, does she stay with her true love or marry for her parent's sake?