Te rascas comes from the verb rascar, which literally means "to scratch". It's a common word, but in this song, it's part of a catchy and very Spanish idiom: si te rascas más te pica.
This phrase translates to "if you scratch it, it will itch more". It's used to tell someone to stop poking at a sensitive issue or dwelling on a problem, because doing so will only make the situation worse. In "Mentira", Ana Mena uses this idiom to tell her ex to stop trying to rehash their failed relationship, as it will only bring more drama and pain.
Mentira is a fiery break-up anthem where Ana Mena and RK trade lines like verbal ping-pong, exposing all the little white lies that have piled up in their relationship. Ana’s verses reveal her moment of clarity: the spark has gone, his eyes give him away, and she is tired of being at his beck and call “para lo que te conviene.” Each time the chorus hits, she stamps a big “Te amo, bebé… ¡mentira!” on every excuse he makes, turning his sweet talk into confetti and reclaiming her self-worth.
RK jumps in to defend himself, insisting that one mistake should not erase the good times, but his protests only highlight the disconnect. Together, their back-and-forth paints a vivid picture of mistrust, frustration, and the messy aftermath of love gone stale. The song’s upbeat reggaeton pulse keeps things danceable, yet the message is crystal clear: when words no longer match actions, the best move is to drop the drama, walk away, and leave those “mentiras” behind.