The act of brushing one's anus with someone else's toothbrush then putting the toothbrush back where it was.
My roommate wouldn't quit hitting on my girlfriend so I gave his toothbrush the ol' cavity creep.
by Ehrensusedtp February 16, 2011
Someone who has bad teeth.
Eww. That cavity creep tried coming on to me.
by Robert MacKenzie August 29, 2005