When someone inserts a toy truck into their partner's anus, then removes it and then rolls it up their back, leaving a dirty trail of tire marks along their spine.
"No more dirty trails tonight! We've run out of hot wheels!"
When a male ejaculates into a female/male's ass, then they proceed to drag their sphincter across the ground (like a dog with ass worms) leaving behind a trail of shit and cum.
Bro, after I fucked that girl in the ass she left a dirty snail trail in my house
Lick a man's ass and Balls,while Giving him a reach around and catching the sperm with your free hand.
One must lickthe man's ass,taint,and balls while Jacking him off at the same time. Works best when the "Licker" is sitting and the man is standing. This provides the best results. MUST catch the sperm in order to be a True "Dirty Oregon Trail".