I hardly ever check out a girl when I think she is looking and I still get caught a lot especially before. like there was a time in grocery store where a girl was at least 15 feet away turned and she turned around and looked directly at me. I personally am wicked obivous (not on purpose) as soon as she goes to turn or look I emidiately look away and if I can't look away fast enough or I no having warning I get into an awkward staring contest and always look away first. I never manage to play it off like everyone suggest
my best guy friends and even my exes have told me all guys check out a chicks ass/body. it's just a natural thing for them. even when you don't think they're looking at you they're looking. which has kind of made me feel self-conscious lol.