Galán translates to "heartthrob" or "ladies' man." It's a classic Spanish term often used to describe a charming, handsome man who is popular with women, especially in the context of soap operas or romantic stories.
In this song, Maria Becerra uses it ironically to expose her ex-partner's hypocrisy: "Pero puertas afuera eres un galán" (But outside, you're a heartthrob). She highlights how he maintains a charming facade for the public while being manipulative and deceitful in private, giving his "telenovela" (soap opera) a definitive end.
Maria Becerra's "ADIÓS" is a super empowering breakup anthem from Argentina! It's all about realizing you were in a bad situation where your heart was being played with, but instead of regretting it, you actually feel like you won by losing that person. She's completely over it, saying "no quiero tus besito' ni tu falso amor" [I don't want your kisses or your fake love] and telling her ex not to send gifts or ask for forgiveness.
She even says "Qué pena me das" [What a pity you make me feel], because he's begging her behind closed doors but acts like a charmer in public. Maria is putting an end to his "telenovela" [soap opera] of lies and deceit. She's done with the damage and the hurt, declaring "A tus engaño' y a tus mentira' le digo adiós" [To your deceptions and your lies I say goodbye]. It's a powerful message of moving on and not looking back at a double life!