My (26M) girlfriend’s (25F) ex keep showing up at her house. What are my options?

My girlfriend’s ex-boyfriend has made a weird habit of randomly driving up and down her street and sometimes just parking outside of her house and just chilling there. It has made the both of us very uncomfortable, especially because he was physically and emotionally abusive to her when they were together. Aside from the fact that it gets under my skin because he’s her ex, I also have concerns for her safety as to what his plan is if he pulls up and she’s out working in her garden or something and I’m
not there.

Yesterday, he showed up again and just parked in front of her house so I told my girlfriend to stay in the house and confronted him for the first time. I didn’t escalate anything, kept it very cordial, and told him to not be coming around here anymore and keep it pushing because it makes us both very uncomfortable. He obviously was very defensive, saying he just likes to smoke here, blah blah blah, and asked me why I was being so weird about it, to which I responded “THIS is weird, you randomly showing up is WEIRD.”

He eventually said whatever he didn’t wanna make us uncomfortable, he’s just gonna smoke his joint and leave and won’t come back. So I told him sounds good and decided to wait there until he finished. He eventually left and I stuck around for a bit longer to make sure he didn’t come back.

I’m hoping that he got the memo and really stays away now that I’ve finally confronted him, but the idea of him continuing to come around makes my girlfriend, and quite frankly me, very anxious, and we want to explore our options. My girlfriend even toyed with the idea of moving in with me, and while I told her I appreciate the sentiment, it’s far too early (we’ve only been dating 6 months), and there are too many logistics such as her big husky which I can’t have in my apartment, as well as what her family will say or feel (they are a very traditional Vietnamese family and I want them to like me).

All that said, what are some options to explore if he does come continue to come around?

tl;dr : My girlfriend’s ex keeps coming to her house, what are some options to explore to stop this?