Remordimiento translates to "remorse" or "regret". It's a strong emotional word that captures the feeling of deep regret or guilt for past actions.
In the song, Christian Nodal sings, "Ahí te va el remordimiento" (Here comes the remorse for you). He uses this word to tell his ex-partner that she will eventually feel regret for her actions and the way she treated him, adding a powerful emotional punch to his declaration of independence.
Christian Nodal is not holding back in "Mi Ex"! This song is all about a relationship that's gone sour because of constant accusations and a lack of trust. Our singer is fed up with his partner always questioning him, saying things like "Que por todo lo que yo haga estés jodiendo" [That for everything I do, you're nagging] and "Que si salgo y no contesto, que a la hora en que me meto y si no estuve con alguien 'toy mintiendo" [That if I go out and don't answer, what time I come in, and if I wasn't with someone, I'm lying].
He's reached his breaking point and declares, "Desde hoy serás mi ex" [From today, you'll be my ex]. And he's not just breaking up; he's turning this breakup into an excuse! He sings, "Mi excusa pa' salir sin un horario y hacerlo a diario" [My excuse to go out without a schedule and do it daily] and "Pa' que no te lo imagines y ahora sí te lo platiquen" [So you don't imagine it, and now they can tell you about it]. It's a pretty blunt and humorous take on moving on from a suffocating relationship, with a bit of a warning that the ex will feel some regret later: "Ahí te va el remordimiento" [There goes the remorse].