My (25M) girlfriend’s friend (25F) disrespected me multiple times after a night of drinking, and I don’t feel like my girlfriend (25F) defended me. Should I keep this casual or end it?

i’ve been dating my girlfriend for a little over 3 months, but we’ve got history — we dated on and off for about 2 years before reconnecting. things were going well until this past weekend, when one of her friends crossed multiple boundaries with me, and now i’m questioning if i can continue seriously with my girlfriend.

for context, i’ve only been around this friend maybe 4 times total. this all happened after a night of bar hopping and drinking, so i understand her friend was probably trying to be protective. i get not wanting someone to drive if they’ve been drinking — i’m not upset about her looking out for my girlfriend. but the way she handled it was so out of line that it completely overshadowed her “protective” intentions.

here’s what went down:
1. when we got back to the area after bar hopping, there was a conversation about me leaving my car parked on the street. i live in los angeles, and towing here is brutal, so when the idea of leaving my car came up, i said, “i’m not leaving my car here, that’s crazy.” before we could even discuss alternatives, the friend snatched my car keys out of my hand.
2. later, she got into my car without my permission and sat in the passenger seat for about 15 minutes, talking at me and criticizing me. my girlfriend came over and told her to get out of my car, but the friend ignored her and stayed another 5 minutes before finally leaving.
3. the next day, the same friend even went to my girlfriend’s house uninvited, after my girlfriend specifically told her not to come over.

the friend still hasn’t apologized to me — only to my girlfriend for not listening to her. my girlfriend says her friend feels she doesn’t owe me an apology and “that’s just how she is, she’s outspoken.” to me, that feels like an excuse for blatant disrespect, and it makes me question the kind of company my girlfriend keeps.

for me, the bigger issue isn’t just the friend — it’s that my girlfriend hasn’t really stepped up to make me feel like something like this won’t happen again. she’s apologized and acknowledged it was out of line, but her actions haven’t reassured me yet.

i told my girlfriend:
• i don’t hold her responsible for her friend’s actions, but i need to see through her actions (not just words) that my boundaries will be respected moving forward.
• until this gets resolved beyond “sorry, it won’t happen again,” i can’t move forward seriously. we can still see each other casually — hang out, sleep over, whatever — but i can’t commit to a full relationship while this is hanging over us.
• if over time she shows she can hold boundaries with her friends and stand up for us, then maybe we revisit being serious.

i’m trying to handle this without punishing her or overreacting, but i also feel like sweeping this under the rug would mean disrespecting myself.

TL;DR: my girlfriend’s friend snatched my car keys, got into my car without permission, ignored my girlfriend when she told her to leave, and hasn’t apologized (only apologized to my girlfriend). my girlfriend says “that’s just how she is,” which feels like an excuse. i told my girlfriend we can keep it casual, but i can’t take things seriously until i see through her actions that my boundaries will be respected. am i overreacting or making the right call?