The verb arropar usually has a warm, comforting meaning, like 'to tuck someone into bed' or 'to wrap someone in a blanket'. It’s an action you'd do for a loved one.
In "Duele," the singer flips this on its head with the line "el dolor me arropa" (the pain covers me/tucks me in). He uses this gentle word to create a powerful and sad image of being completely enveloped by his sorrow, as if pain itself is a heavy, suffocating blanket he can't escape from.
This song is pure, unfiltered heartbreak. Reik's lead singer, Jesús Navarro, starts by asking his ex why she left so suddenly, without a word. He sings, "Si nuestro amor se acabó / Me lo tenías que decir" [If our love was over / You should have told me]. He's trying to be strong, but everything reminds him of her, even the smell of her perfume in the house. The chorus is just a simple, painful repetition: "Duele quererte así / Duele extrañarte así" [It hurts to love you like this / It hurts to miss you like this].
Then, reggaeton legends Wisin & Yandel jump in to turn the drama up. Wisin's verse is especially intense, comparing his suffering to being shot at point-blank range ("disparándome a quema ropa"). He feels completely discarded and can't go a minute without thinking of her. The song ends with the singer feeling like he's going crazy, seeing his ex when she isn't there and admitting he wasn't perfect ("no fui un santo" [I wasn't a saint]). It's a classic Latin pop track about a breakup that leaves you completely lost.