A Homosexual man that rides the knob/head of the penis to minimize penetration/painfulness during anal intercourse. Similar to Knob Jockey but to an extreme level.
An anal retentive (tight assed) person that won't do a friend a small favour. The payout factor is that usually during sex the entire penis (shaft and knob) penetrates or is ridden. This meaning suggests that via being a knob jockey and not a cock jockey that they are not giving the other party the satisfaction of riding the entire shaft rather than just the knob. Somewhat of a bastard. A Knob Jockey of the highest order could compete at a national level.
Tony: That lad is some Grand National Knob Jockey.
Pat: Oh stop I’d say he never gets off it!
Hank: What is the Gibbins lad like?
Harry: Well to be honest, se is no less than a Grand National Knob Jockey!