The creepiest look in the world, seriously the creepiest way one human being can make eye contact with another, is the Unfriendly Ogle.
There's a couple breeds of ogles, and I don't necessarily mind them all. There's the Ogle With A Permission Slip, where a guy you're partners or close friends with makes a show of looking you up and down just to tell you he likes what he sees. There's the Hey There Ogle, which turns into a smile and frequently a pickup line when he sees you looking back. There's the Shy Ogle, which instantly evaporates and turns into intense contemplation of a nearby blank wall when he sees you looking back.
Some ogles are a little more uncomfortable. Like the Titanium Ogle, which cannot be broken by disapproving looks or the passage of time; those eyes stay locked on until you either start a fight with him or hide behind something. And its close cousin the Drive-By Ogle, where the body is just passing by but the eyes don't move until his neck won't physically turn that far. And the super-awkward Over The Girlfriend's Shoulder Ogle.
But few ogles are straight-up frightening like the Unfriendly Ogle. This is where the guy ogles with a really stone-serious face like he's reading the obituaries, and when he realizes you noticed him, he scowls at you. What the fuck is that? I've gotten it a few times (and yeah, I'm pretty sure it was a bona-fide ogle and not just a glare for other reasons), and I don't even know how to interpret it. My best guess is "I know you'd turn me down like the other bitches so why bother trying." But there's also the charming alternate possibilities of "what a slut you are for turning me on like that" and "being horny for me is actually the same feeling as being mean."
Whatever it means, I don't like it. At least smile when you look at me like that, creepo.
It's funny, I used to feel like I never got ogled or catcalled, but in the last year or so I've been getting a lot more. I'm not entirely sure why. Maybe I'm just more aware of it?