I non-rev home to Atlanta, yesterday, after a long weekend with my girlfriend and he daughter in [Content Deleted]. The standby list was looking horrible for the [Content Deleted] flight. I noticed a short-haired non-rev, with 4 kids. …..I went up to the desk and asked the agent to put me on the jumpseat, then I headed down the jetway to talk with the captain. The conversation went as follows: ……….ME - "Good afternoon Captain. My name is Richard, I am a Delta pilot, and I am supposed to be a non-rev in back. There are lots of folks up at the gate trying to non-rev, including a pilot and his 4 kids, so I figured I would jumpseat, to free up a seat for another employee. However, I do have a shirt with a collar, but no dress pants. I only have these jeans I am wearing. "…………. Captain- "Ummmm, I don't know about that….." ……….. First Officer-"F*&^ him, he should have bought a ticket!" ………. Me-"He is a fellow Delta pilot, traveling with 4 children." ………. F/O-"Like I said, F*&^ him! He could have bought a ticket, just like any other passenger." …….. Captain-"I'm sorry, but I can't allow jeans in the cockpit." ……..Me- "Thanks anyway, I figured it couldn't hurt to ask." Although I wish the Captain was an outside-the-box thinker, I respect his decision. However, I was blown away by the loser in the right seat. Perhaps he was flexing his 5' 6" Napolean complex, but what a dork. I can guarantee he will not get the jump seat on any flight I am working.