Fronteaban comes from the verb frontear, which literally means 'to confront' or 'to face'. However, in urban and reggaeton slang, it often takes on the meaning of 'to show off', 'to challenge', or 'to boast' in a confrontational way.
In this song, Kevin Roldan uses it to refer to those who used to challenge him or show off against him, asking, "Los que me fronteaban ¿dónde están?" (Those who were confronting me/showing off against me, where are they?). It's a key word that captures the competitive and boastful tone common in the genre.
In "Llano Grande," Kevin Roldan paints a picture of a lavish lifestyle filled with success and confidence. He calls himself a "world star" and dismisses his critics, saying they are now like "fans" waiting for him. The lyrics are full of boasts about his wealth, mentioning a mansion that looks like a hotel, a large property in Llanogrande (a wealthy area in Colombia), and luxury items like Rolex and Cartier watches. He declares that no one can compare to his status as a "gangsta" from Cali.
Amidst all this bragging, the song is also an invitation to a woman he's attracted to. He tells her, "If you like me and I like you, let's go together." He invites her to a secret party at his mansion in Llanogrande, telling her to let her boyfriend know she'll be late because she's with the "multimillionaire from Llanogrande." The lyrics describe his intense attraction, wondering if it's her face, her hair, or her body, but knowing her kisses take him to heaven.