1.Refers to when a person is persuing another person with extreme effort, usually because they are attracted to them or have sexual attraction for that person.
2.It can also mean; on someones case about or for something. Bothering them
fat girl: i am always the third wheel skinny girl: girl, you the third and fourth wheel fat girl: i am sick of the fat jokes
skinny girl: i am just jocking on your bitch ass fellow homosapien of the world