Mujeriego translates to "womanizer" or "ladies' man." It's an interesting word because it describes a specific type of person and behavior, often with a negative connotation, making it more unique than common verbs or nouns.
In the song, the singer explains, "Por eso uno se hace mujeriego / Por mujeres como tú" (That's why one becomes a womanizer / Because of women like you). He uses this word to express how heartbreak has led him to adopt a lifestyle of not committing to one woman, blaming his past experiences for his current behavior.
Virlan Garcia's "Corazón Frío" tells the story of a man whose heart has turned cold after a painful breakup. He admits, "Frío el corazón por tu partida" [My heart is cold because you left], and he's become someone he barely recognizes. He wasn't always this way, but the heartbreak made him a drunk who doesn't believe in love anymore. He doesn't care if he makes others cry, even those who might truly love him.
The lyrics reveal his inner struggle as he wonders how he'll explain to his heart that her energy won't be there anymore, or how he'll cope with not having her close to kiss and caress. He's tired of pretending to be happy, and his smile is exhausted from faking it. Even though he knows she's leaving and "nada es para siempre" [nothing is forever], it still hurts him deeply. He even admits to dreaming of her and thinking about going back, but ultimately decides he's worth more than an infidelity. He declares, "por nada del mundo he de volver" [for nothing in the world will I return], even though the pain is real.