The phrase se me fue is a powerful way to say 'he/she left me'. It uses a special Spanish structure that emphasizes the speaker's personal sense of loss and lack of control over the situation.
Instead of simply stating that the person left, this phrase implies it happened to the speaker, making the line much more emotional. It's a perfect expression of heartbreak when someone disappears from your life unexpectedly, which is exactly what Becky G sings about.
This song is a back-and-forth between two people breaking up, and it's full of mixed signals! One minute they're saying, "Me muero por ver / Tus ojos al volver" (I'm dying to see / Your eyes when you return), but the next, it's a cold shutdown: "No se va a poder / Por más que lo intente / Te tocó perder" (It's not going to happen / No matter how much I try / You had to lose). It feels like a conversation where both people know it's over but can't quite let go of the good memories, or the love that's still there.
They both admit they made mistakes that can't be fixed, calling it a "Cuento de nunca ya acabar" (A never-ending story). The solution they land on is to just accept it and go their separate ways: "Vamos a aceptar / Tú por aquí, yo por allá" (Let's accept it / You over here, me over there). But even after deciding to split, the feelings rush back in. One of them mentions buying expensive gifts like Chanel and Cartier, only for the other person to leave. The song ends on a really sad but honest note, admitting that even though they'll never see each other again, the love is still real: "¿Y eso qué? / Pues te amo, bebé" (So what? / Well, I love you, baby).