Muddy Tire
A sexual act where one partner gives the other a Rim Job except the recipient failed to wipe their ass after their last shit, thus making the rim/tire muddy.
After taking a shit i realized there was no toilet paper to wipe my ass with, so i called in my girlfriend and had her give me a muddy tire.
muddy bike tire
The act of pulling your poopy dick out of someone's ass and giving er a good slap on the back causing the impression of riding bike with a muddy tire! -MDS
Muddy bike tire on ur back
Muddy Bicycle Tire
When during Anal intercourse (the woman may need to have diarrhea) the male pulls out and smacks his dick on the females back near the tramp stamp area. This will cause a lot of the fecal matter to be flung off and leave a trail of shit up the spine.
you dude i gave that bitch the muddy bicycle tire last night and she spent an hour in the shower trying to get the shit off! hahaha she couldn't reach it!!