A person who stings another's ring - ie a homosexual who sticks his old chap in another man's ass and makes it sting. Of course, if the other man is loose and enjoys this exercise, it will not sting at all.
'Man, that guy was a real ring stinger.'
Another term for the coveted 'knackers' enclosed in the scrotum
'Oh shit, the ball just hit me in the wrinkled walnuts.'