ABS is short for awkward body shape. For example, this could be someone with an abnormally large upper body, and tiny skinny legs. Or someone with big legs and a tiny torso. There are many different kinds of awkward body shapes.
I thought that girl was hot when I saw her sitting down, but then she stood up and she has a serious case of ABS.
An amusing way to say you are a pervert, inspired by the common saying "Naughty is using the feather, perverted is using The Whole Chicken!"
"I like to use The Whole Chicken, if you know what I mean, wink wink, nudge nudge..."
or
"Man what a disappointment, this site is called The Whole Chicken yet it is only nude art and fetish reviews. They might use the whole chicken, but they don't seem to show it on there."
or
"So what about you hun, you use the feather or the whole chicken?"