Death Eaters Light

What if before Lucius and Narcissa got married he and Bellatrix had a fling and Bella ended up pregnant? I will be introducing you to the illegitimate daughter of Lucius Malfoy and Bellatrix Lestrange. She is less like her mom and more her own person with dark tendencies. I'm bad at summaries please read if you like Severus Snape X Original Character.