This is in reference to a major asswhooping in either gaming or real life. The term "that asshole is whistling" is like saying they got so beat down that when the wind blows their asshole is whistling like a beer bottle.
You catch the fight last night on pay-per-view? Friend: yeah man, that ASSHOLE IS WHISTLING! He aint gonna shit right for a week!
by Grumpy gilmore April 27, 2021