Caprichoso translates to "capricious" or "whimsical". It describes someone who is prone to sudden, unpredictable changes in mood or behavior, often acting on impulse or whim.
In this song, the singer admits, "sé que soy un caprichoso a veces mal hablando" (I know I'm capricious, sometimes speaking badly). This self-awareness adds an interesting layer to his character, showing vulnerability and acknowledging his own flaws in the context of a relationship. It's a less common word that offers a deeper insight into personality.
Mario Luis's "Amor Inventado, No" is a heartfelt plea from a man who realizes he's messed up in his relationship. He sings about falling asleep, thinking he was wrong to want his partner to be "perfecta" [perfect], and how he took her for granted. He admits to his flaws, saying he's "caprichoso a veces mal hablando" [capricious, sometimes speaking badly], and he's now desperate to win her back.
He doesn't want her to think their love was "un amor inventado" [an invented love] because he knows she's hurting. He promises to change, vowing "en esta vida hoy lo cambiaré" [in this life today I will change it], and begs her to return to his "castillo" [castle] where he, her "rey" [king], waits for her and all her "locuras" [craziness]. It's a sweet, almost desperate, declaration of love and regret, with him promising to always love her, no matter what.