That awkward moment you catch someone checking you out. So after a few seconds, you check them out to see if they’re still checking you out. And in doing so, they catch you checking them out.
And so you wait a few seconds and then check them out to see if you catch them checking you out again and wonder if they’re wondering what you’re wondering.
“Are they checking me out to check me out or are they checking me out to check out if I was checking them out?”