This might sound strange, but I'm not going to tell someone to quit hitting on my girlfriend.
Indeed it does. Are you OK with that?
I don't know, should I tell them to quit it? Then my girlfriend is going to notice that I don't like it and that would feel weird.
II think you're right in you thinking. You can't really control what other people do. If your gf is fine with unwanted attention so should you.
I don't know. Maybe I should tell them to stop.
You sound confused. You need to sit down with your girlfriend and have a respectful talk about how you're going to handle these situations.