The McGarrigle twins were students at Mid-City Jr. High who bullied Charles and Mambo in The Girls of Route Canal.
In the episode, they threw them in the trash can, and the next day they beat them up in the cafeteria when they attempted to confront them.
They gave them each a black eye, broke Charles' arm, broke Mambo's leg, sprained Mambo's neck, cut Charles' cheek and bruised his head.
They also seemingly bullied their girlfriends, Amanda and Alexis, into dating them.
They're very upfront towards them, and very blunt about going out with them.
The McGarrigles would often drag them by their arms, and refer to them not by their names, but by unsavory nicknames.
By the end of the episode, Charles and Mambo had the McGarrigles deported to Albania, so they could get time together with Amanda and Alexis at last.