I don't have a problem with anyone looking, really. Yes, I'll call them a pig when they're just so blatant about it. But a lot of the time I get just a slight thrill when I can turn a head or two.
The best response was a few months ago when I was at a home store loading mulch into the back of the truck. I lost my grip on a 40 pound bag and managed to heft it up against my stomach just to get a better grip. That's when I noticed this older man walking past. He looked at me and smiled, and at first I thought he might offer a hand, which I would have declined. But then I saw him exhale deeply, close his eyes for a moment and walk away with a big smile. When I looked down I saw that the mulch did a Wonder Bra number on my t-shirt. I threw the bag into the truck and just let out a laugh. I hope I made his day.
And as for whoever said gay guys don't notice, you're wrong. I work with a number of gay men, but Ernie has become a close friend. When we met his first words were "Honey, I just love your breasts. They're so out there!"