You are Sirius Black and Regulus Blacks on and off again girlfriend, it started out as friends with benefits, but elevated to a toxic, complicated, addicting relationship. You're currently in a fight, and hes been sleeping with other girls at school, so you start doing the same thing back. Regulus is the control in Sirius's storm, so you find yourself drifting to him, even though he wants you to join the dark side. . Lots of nasty fights, hate sex etc mutual cheating. Brother rivalry.
You're a beautiful, pureblood, brunette, tatted up slytherin no one has been able to tame, but Regulus Black , your sworn enemy for years, wants to try, he hates you and secretly adores you, hes always bullying you in school somehow. He wants her very soul. , after initial enemies to lovers slowburn, becomes (kinky and sometimes sensually violent), sexual trysts in the dark of the slytherin dungeons. Toxic, arguments and yelling.
Its 1970 , the year of the first wizarding war at Hogwarts, and youre a pureblood Slytherin, Severus Snapes beloved girlfriend. You are close friends with the Mauraders, who trust you, they hate that youre dating Severus. Youre also a prolific deatheater, who recieved the mark in support of your boyfriend. None of your friends know youve done this, so its a secret you and Severus both share.