Oveja negra literally translates to "black sheep." It's an idiomatic expression that refers to a member of a group or family who is considered an outcast or disreputable, often due to their unconventional behavior or reputation.
In this song, the phrase is used to describe a woman who, despite coming from a "good family," is seen as rebellious and wild. The singer repeatedly calls her "la oveja negra" because of her flirtatious nature and her disregard for social norms, making it a central and memorable theme of the lyrics.
Darío Gómez brings us a classic tale of a man who thought he had a woman figured out, only to be surprised by her true nature. He starts by saying he's good at analyzing women so he doesn't "caer con cualquiera" [fall for just anyone]. He was making "cuentas alegres" [happy plans] with her, believing she was from a "buena familia" [good family]. But then, plot twist! He realizes she's the "oveja negra" [black sheep] of the family, despite her seemingly good background.
He describes her as having a "mirada engañera" [deceptive look] that could fool any man, beautiful on the outside but "por dentro muy loca" [very wild inside]. He laments that it's a shame she's so "traviesa" [naughty] with anyone who kisses her. Despite all this, he promises to be discreet, saying "a nadie diré quién fue la oveja negra" [I won't tell anyone who the black sheep was], even if her reputation spreads like the wind. He even calls her out for acting innocent now, "con cara de yo no fui" [with a 'it wasn't me' face], as if she doesn't know him. He makes it clear that he's the one making the decision here, and anyone who doesn't follow his "ley" [law] is out. It's a pretty blunt take on a relationship gone sour, with Darío Gómez's signature style.