Do I turn in my manager I hate?

Okay so there is this manager at my work who it a total bitch to me ever since I started. She treats me like I am a moron but this is my first ever like for real job I have had others but those were all seasonal or temp. I have been at my job got nearly a year but she still treats me like I don't have 2 braincells to rub together. But I recently found out she is dating upper upper management which you are ABSOLUTELY NOT allowed to do and I am deciding weather to turn her in and get her eather a. In trouble (best option) or b. Fired (okay option though I'd feel bad) what do y'all think? ( we are also both lesbians so I do feel bad hating her but she is a massive bitch so)