ordering octopus at a tapas bar 

Thinking you are going to win at fantasy football but getting schooled by someone who knows nothing about the sport.

Eric got destroyed in fantasy football. It's like he is ordering octopus at a tapas bar.

ordering octopus at a tapas bar by cockodoo September 8, 2010

Getting a hot dog at a dive bar 

When you go to a dive bar and take part in the glory hole

Tonight we’re going out and getting a hot dog at a dive bar

Getting a hot dog at a dive bar by RichardArmy March 30, 2019

Sweating like a fat bird, in a bin bag, at a barn dance 

When a person sweats profusely due to the overexertion of a physical activity.

Dan : "Hey Abbie, how's the workout going?"
Abbie : "Yeah, really great thanks. I'm sweating like a fat bird, in a bin bag, at a barn dance!"
Dan : "Good work, you won't be a fat fucker for much longer!"

Sweating like a fat bird, in a bin bag, at a barn dance by scooner March 21, 2018

Barking at a knot 

A useless or impossible task. Often a waste of ones time. Cowboy slang

The guy was barking at a knot when he was trying to hook up with that girl.

Or

Yer barking at a knot . There is not way you can take that stallion.

Barking at a knot by Cowbae October 3, 2018