What are some things that the opposite gender thinks they're being sly about?

[AmandaYVR]

This is a good q. I'm just having a hard time coming up with good examples to answer it.

I remember once in my 20s at work, I was wearing a dark grey one piece bodysuit, sort of a mock turtleneck, those kind that always accentuate the bust (although that's not something I was aware of at the time or why I bought it.) I worked at a high-end retail place, with lots of men in beautiful suits, and the environment was upscale and it was an interesting dichotomy of composed and classy and gettin' wild at night. We worked hard, played hard.
So one of the many managers and I were talking about whatever work thing one day, and he glanced at my chest one too many times, and then I guess he noticed I noticed, and says, "That's a very nice top you're wearing today, Amanda." I said thank you and moved on, but it does make me sort of chuckle, in retrospect. I do think how he handled it was fine. Many guys would ignore the glance and just not say a thing, but that was his method.
So yeah, long story short, we do notice when you look. But I don't blame guys. They're there, front and centre. Cleavage, no cleavage, it's understandable. We notice them as well. It doesn't have the same effect, but yeah, hard not to notice them when they're out.

As far as checking people out, walking down the street... I can't tell if you're looking. Never really have. I wear sunglasses and so do you. I don't want to be caught looking anymore than you do. So I look away, I think just in time, but who knows.

Sorry, I can't think of any better examples.

[Zivasaur]

First, I'd just like to say that this is a really cool question. Interested to read future comments!
Secondly, I'm going to go a different train of thought than my fellow commenters...

Right off the bat - guys hiding boners.Depends on the method you're using obviously, some are more obvious than others. But that one where guys hold a book or a bag infront of their crotch is an easy one to spy. Or when they pull their shirt over their crotch when seated.

[bamesjond0069]

When you fuck us right away we know youve done it before. Saying "I've never done this before" is so fucking bullshit. Lmao.

[Snakeyes7]

Bold of you to assume I even get such opinions from them.

[sklirókorítsi]

We know all the lies that have been told to deceive a girl, but they continue anyway.

[SpaceGalaxy]

Girls acting innocent even though they have real naughty thoughts which they have acted on

[KrakenAttackin]

Girls cheat a whole lot more than they will ever admit to. I have seen this first hand, many, many, times.

[Agape93]

“Accidentally” poking into the butt.

[Iamcoming]

Test on boys

[Acidgamer]

She is "fine"