Desquítate is a powerful command that means 'get even' or 'take it out on me'. It comes from the reflexive verb desquitarse, which means to get revenge or get back at someone.
In this passionate song, Romeo Santos invites a heartbroken Rosalía to 'desquítate con rabia pasional' (take it out on me with passionate rage). He's telling her to use their encounter to release all the anger from her previous relationship, turning her heartbreak into a form of healing.
This song is a conversation between two people who just got dumped. ROSALÍA kicks things off by saying she's heartbroken because she's in love with someone who doesn't love her back: "estoy enamorada / Y no soy correspondida" (I'm in love / and it's not reciprocated). Romeo Santos jumps in, saying, "Igual que tú, no tengo suerte en el amor" (Just like you, I'm not lucky in love). They find common ground in their misery, agreeing that loving blindly is a bad idea.
Instead of just crying about it, they come up with a plan. They decide to use each other to get over their exes. The chorus is a direct invitation: "Te incito / A aliviarnos las penas y curarnos en la cama" (I invite you / To relieve our sorrows and heal ourselves in bed). Romeo promises to be her "pañuelo" (handkerchief) to dry her tears, and they both offer to be the cure for each other's pain. It's a very practical, if temporary, solution to heartbreak.