I’m (19m) uncomfortable with my girlfriends (18f) dad sleeping over at her place

So my girlfriend just moved out and shes been nervous to live on her own but she finally did it and im really proud of her. But recently (maybe 3 weeks after her moving in) her dad started sleeping over and basically just living there for 2 days at a time then taking a few days off and then doing the same.

This I wouldnt have a problem with if it wasnt for the fact that her dad has repeatedly sexually abused her in the past when she was young. And the whole thing just makes me feel off. Im scared he’ll do something again.

My girlfriend has had a lot of family problems and stuff but this is tricky for me cause i dont even know how to bring this up to her

As im writing this she just told me her dad is now officially moving in with her so theres that.

Am I weird for thinking this? How do I bring it up to my gf?