WIBTA if I revoked my sister's access to my streaming accounts after she shared my passwords with her boyfriend without telling me

So this is maybe a smaller deal than it sounds but it's been bothering me for like three weeks now and I need outside perspective.

I (22F) share my Netflix and Spotify with my sister Jade (26F) because we split the cost of the family plans. It's been working fine for about a year, we each pay half, no issues. Last month I noticed a new profile on my Netflix that I didn't recognize. I asked Jade about it and she casually said oh yeah that's Marcus, we've been watching stuff together so I just added him. Marcus is her boyfriend of four months.

I want to be clear that I don't dislike Marcus. I've met him twice and he seems fine. But she didn't ask me! She just gave out my account login to someone i've never really spoken to, without a single text saying hey is it okay if Marcus uses it too. It's my account. I'm the one whose card is on file. If Netflix flags it for sharing outside the household thats on me not her.

When I brought it up she got kinda defensive and said I was being weird about it and that it's just Netflix. Which, okay, maybe. But it's also just basic courtesy to ask before sharing something that isn't yours? I told her it made me uncomfortable and she rolled her eyes and said I was making a big deal out of nothing.

Now I'm considering just quietly removing the extra profile and changing my passwords. I'd still split costs with her for her own access, i'm not trying to punish her. But I don't want Marcus on my account if she can't even be bothered to ask first.

WIBTA?