Allá tú is a common colloquial phrase that literally means "there you". It's used to put the responsibility for a decision or its consequences onto another person, similar to saying "That's on you" or "Suit yourself".
In the song, the singer says "Allá tú si te alejas de mí" (That's on you if you distance yourself from me). It's a powerful expression of resignation and defiance, telling his love that the choice to leave is theirs to make—and their burden to carry.
Inseparables brings together Yahritza Y Su Esencia and Ivan Cornejo for a classic, stubborn tale of young heartbreak and defiance. The track kicks off with someone refusing to let go, insisting to their partner, Diles que tú a mí me quieres ("Tell them that you love me"). There is pure late-night restlessness here: driving around aimlessly, waiting for a call, and strumming a guitar in frustration. One narrator even mentions listening to the song Perro Abandonado to match their mood, bluntly adding, así me dejaste ("that is how you left me").
Family drama makes the situation even messier. Parents step in to say no me mereces ("you do not deserve me"), but nobody is listening to reason. Instead, the lyrics double down with a shrug and a warning: Allá tú si te alejas de mí ("That is on you if you walk away from me"). The phrase allá tú is a great Spanish idiom that translates roughly to "suit yourself" or "on your own head be it." It balances desperate pleas like Quiero que me ahogue en tu calor ("I want to drown in your warmth") with the petty confidence that their ex will never find another love like this.