Vaivén translates to "sway" or a rhythmic "back-and-forth movement". It's a fantastic, dynamic word that perfectly describes motion and rhythm.
In the song, Kapo sings "Que me tiene loco / Con ese vaivén" (She has me going crazy / With that sway). He's captivated by the mesmerizing way his partner sways her hips when she dances. It's a word that not only sounds cool but also perfectly captures the dancehall energy of the track.
This song is all about being completely obsessed with someone you can't be with right now. The singer is stuck, literally "Parqueado en el mismo lugar donde te conocí" (Parked in the same place where I met you), and can't stop thinking about this person. It's a classic case of longing. He feels trapped, saying "Me encierro en cuatro paredes" (I lock myself in four walls), and everything on the radio reminds him of his love. His solution is pretty romantic: he tells her to "Mira la luna y siente que estoy al oído susurrando" (Look at the moon and feel me whispering in your ear).
He then remembers how he won her over, starting with a rose and some dancehall moves. He's convinced their connection is special, a love you just don't see anymore: "Una historia tan hermosa / En estos tiempos no se ve" (A story so beautiful / You don't see it these days). He's not shy about his feelings, telling her every day how beautiful she is and how her dancing, her "vaivén" (sway), drives him crazy. It's a sweet and passionate song about a love that feels totally unique.