A person who somehow ended up becoming friends with everybody even though they don't have any social skills. Those people often go to them for advice and problems, because it seems like they have their life in order.
Person 1 : "Man, i can't choose between A and B."
Person 2 : "Oh! you should go to Jonelis with that"
when someone is trying to pull a fast one or a trick or scam they are said to be pulling a backdoor jones. Also there is the antonym known as the backdoor jones on the fronstide.
An employee tried to make the boss believe they were sick in order to go home early. He is said to be pulling a backdoor jones.