When guys hit on girls at the gym when they're clearly not interested, (and vice versa), and won't take the hint. This is particularly for older ones who are looking for arm candy/trophy wives/husbands and, from personal experience, especially ones who are my mom's age and my mom is standing right there
. I'm in a crappy t-shirt, sweat pants, and have a ten pound biology textbook in my hand; do I REALLY look like the type to be into that?
And people wonder why I take the time to drive to an all-women gym.
Well, okay, this really isn't isolated to gym instances, but it seems to happen to people the most there.