check your oil
ramming your fingers up someone's ass
Hey, let's go check his oil!
check your oil
When someone pisses you off enough that you threaten to stick something, like your foot, up their ass.
Dude, if you don't stop that shit, I'm going to check your oil.
check your oil
When you run your finger across your bunghole in order to be certain that you wiped good enough.
I checked my oil and now I know how those stains got in my underwear.
checking your oil
When one inserts their finger in their own anus in order to gauge their personal stink level.
Don't touch me bro, you been checking your oil
Check your oil
A prostate exam.
I went to the doctor because my nards were sore and the SOB checked my oil.
Checking your own oil
When a man is able to fold his penis back and stick it in to his own anus.
Have you ever heard of checking your own oil? I'm sure Ron Jeremy has done it quite a few times.