The act of one male approaching another male from behind and putting his hand in between the back of his upper thighs and moving his hands in a back and forth slapping motion.
This act must be performed while calling out the phrase, "grimy trout!"
This motion is an exact replica of the male trout swimming up stream during mating season.
To be extra grimy, the man will move his hand in an upward motion, coming in contact with the male genitalia, testicles, and or gooch. This motion is done while calling out the phrase, "grimy trout, swimming up stream!"
The act of performing a grimy trout should never be done in a homosexual way, but only as a friendly way to say, Hi, or How are you? It can also be done to people who you really don't like and want to humiliate in public.
If not done in a friendly way, only grimy trout chaches, frat stars, and others who you really don't like.
grimy trout- Wow Paul, that grimy trout really was the grimiest thing that anyone has ever done to a chach like me.
Woa! What did you just do to me?
You know you liked that grimy trout fag.