I wanted to give the benefit of the doubt that this is Monica getting to play a villain, because villains are fun to play. A lot of actors enjoy playing villains because they understand it's just make-believe, but it gives them a chance to step in the shoes of someone who they're not, whether to better understand them or let out some frustrations in an "in character" moment that they wouldn't do in person. Vic is the "oddball" in that while he has played villains in the past, he has set standards because he puts himself into that role, perhaps may even see himself in that character just a little bit. Hell, in one of his Sunday sessions, he says that the actor who plays Judas isn't necessarily a bad guy in person (and neither was Judas for that matter, he just had questionable morals but ultimately regretted them), but someone's gotta play Judas. Therefore, outright unapologetic villains are his turn-off (so being Hitler may be one of his "no-no" roles, but he understands that someone has to play him).
But... Anna's not exactly a "villain". She's an antagonist, but she's not evil, she's just a horny teenager who literally doesn't understand why because her mother is a grade-S cunt who believes sex is evil and is enforcing that mindset onto society. Still, though, she's really uncomfortably extreme about her feelings toward the main character. If Monica is really and truly a rape victim and it still bothers her to this day, she wouldn't have continued to play the character (from my understanding, if you're not at all familiar with the series in question, auditions don't give away the character entirely and you just get a picture and maybe a sentence or two of their personality, though pigeon-holed casting is a thing). Stocking is in the same vein, but more along the lines of sex jokes than being an outright rapist.
But given that she lol'd on Instagram over a mug Soye gave her about punching his current fiancé to be with her instead, she's either self-loathing or has some fucked up fantasies and has to lie to hide it. Really, anyone who brags about their sex lives to a bunch of strangers online have some deviant or depraved fantasies and are part of the "Don't kinkshame me!!!" crowd while still trying to hide behind their victimhood card.