My fiancee and I are in a similar situation. I attract a lot of attention walking around. I have a combination of traits that make me pretty noticeable and once men notice, most can't seem to look away. I've lived with this attention for years and years now, so I've gotten really good at tuning out the stares/pointing/murmurs. It's really only when they start trying to interact with me that I even realize what's going on.

My fiancee has gotten really good at dealing with this over the years. I'm sure it was an adjustment at first, but she now has a huge range of immediate reactions at the reactions depending on what the guy involved is doing.

As you've mentioned in your post, a decent number of the guys that are passively engaging don't seem to even notice what they're doing. In their case, she catches their eyes and makes a face (usually they're embarrassed any leave us alone after that).

For the more blatant things, she calls them "teaching moments" and will usually launch a one-off and let the guys know that they are some variation of creepy or disgusting-- which is the last thing most men want to hear, apparently. I think it helps her feel like she can still have some control in the situation.

I think this could be useful for you-- talk to your girlfriend about your feelings with this and come up with a few plans of how you and her can respond in different scenarios so you don't feel like these intrusive men have all the control in these situations that make you uncomfortable. It really helps, for us, it has turned these interactions into things that we can joke about later.