You are Not the Asshole OP. I talked with my bf about it and it is a strange thing to do. But i suggest to wait until you notice more strange things before you ask about anything. I'm not encouraging assumptions because there's nothing wrong to ask about strange decisions like this that make you uncomfortable(getting in/inviting strangers to drop them off at home alone at night; that such behavior). It is concerning and draws up red flags and there's nothing wrong with stating what makes you uncomfortable or concerned for her safety. But please notice for more things before anything else gets brought up with this situation unless you're 100% sure her safety is in danger. I'm sure everything is fine and it's just a strange fluke. But you care about her and there's nothing wrong with worrying about things like these, unless there's further evidence that can make you feel like she's cheating(I'm not saying she is) or in danger(I'm not saying she is); I don't think its anything to worry about or dwell on enough to fight. I'm sure you know what helps you feeling better, but stepping away from this action (but not forgetting) will do good for your thoughts. Because it will let you notice something about her you may not have noticed before, like she helps people or hitchhikers or friends or family like this often. But its also good to protect your feelings from scary thoughts by making sure she's also okay. Its gonna be okay, but some space, faith, and communication is always a healthy start to talking about actions your SO makes that make you feel concerned or worried about their safety. Its gonna be okay :)