When you exit the bar, house, job, relationship, etc without the typical niceties or bothersome social morays.
Similar to an "irish goodbye."
Randy and Joe were out for a day of skateboarding around the city. Randy was excited to try out his new board and jetted off in front to lead the pack. When he slowed down to share with Joe how great his new board was, Joe was nowhere to be found. Joe didn't like his socks and had decided 10 minutes prior that he was going home. Randy thought to himself, "damn, I guess Joe 35th'd it again."