So, I don’t know your ex, and I’m not commenting on her. I don’t know your circumstances.

I do know old fandom people who chose Slytherin as their house.

The choice of Slytherin in fandom is more complicated than it sounds, esp. since when the books were at their height of popularity, the wizard/white supremacy undertones of the books were taken more in a “oh, here’s yet another basic black and white symbol from the author of why the bag guys are extra bad” rather than the actual problem we have on our hands 25 years later. (And fuck the assholes who decided to make it a problem relevant to current events. Fuck them with a rusty saw.)

People who actually have a pretty strong moral compass that’s compassionate and inclusive often ended up self-catagorizing as Slytherin back in the day, because in real life what happens is that if you’re gay/bi/trans/whatever growing up in a conservative household, or an intellectual, or dealing with ADHD or autism or the like, and living in a conservative household, you’re basically turned into the black sheep of the family through family presure.

Like, you’re pressured to not be a smarty pants, pressured to be neurotypical, pressured to not be a “sinner” that is “choosing” to be gay or trans or whatever. And in that era (late 90s, early 2000s) you’d often also be bullied at school for the same things, by the local popular/jock type people. And that type in the books is Gryffindor. And Rowling even has Harry’s parent’s generation bullying Snape as canon.

(Rowling is actually a pretty good MIMIC of human behavior, but from her words and actions recently I can see she doesn’t actually understand much of what she writes about. She’s like a lyrebird, adeptly matching a sound she heard without being able to understand what’s going on on the human side of things. So she writes characters that are vivid, but she sucks donkey balls when trying to get the psychology underneath and the morality beneath right.)

Anyway. So Snape (or Draco) and Slytherin was sometimes more comfortable for people actually already being outcast in real life. Because growing up poor in a shit home with an abusive dad and being bullied in school too was something a number of fans lived themselves.

The thing is, conservative households happily persecute the smarter/more empathic members in their family and drive them away. And thus some of those people end up as goths or punks or involved in similar communities, and Slytherin is closest to that. So you end up with people dressing in black, but still being more accepting of people who are different or strange than the people trotting around with crosses on their chest or wearing more traditional styles.

Interestingly, I’ve recently had some experiences which had me mingling with a different social class than I usually do, and I realized there’s two types of tatted up people. There’s the nerdy, arty intellectual types–band kids, librarians, writers, etc–and there’s folks with criminal or addiction histories. But “normal” people see tats or whatever and throw both types into the same bucket.

But because Harry Potter was a nerd fandom, I always assumed any fan I interacted with was probably an intellectual (because why would people not into books get into a book fandom?) and thus them picking Slytherin probably meant they went through some sort of shit at home.

But maybe the fandom got big enough to break boundaries and get enough non-book fans that that’s no longer a great assumption. I haven’t been in the fandom for at least 15 years, closer to 20, so ::shrug:: I would be suspicious of a NEW fan selecting Slytherin, but not an old-school fan unless they had other behavior that was off.