When two to four guys are interested in the same girl and form an alliance in order to get the girl to like them and share. When there are more than four guys it is called busing. See polygamy or mormonism.
Bro 1: Yo bro, I hear you like this girl, too.
Bro 2: Yeah, bro. What about it?
Bro 1: You wanna form an alliance and carpool?
Bro 2: ....Yeah. We can go carpooling.
Carpooling- since sports make people tired out but yet they get exercise, carpooling can be considered a sport because you also get tired out by watching the people you are with in the car and making sure they dont cause trouble. and you get exercise by yelling at them and telling them to shutup and sit down so the cops dont see them when you run a red light.