Pegado literally translates to "stuck" or "glued." It's a common word, but in the context of this song, it takes on a fun, colloquial meaning.
The song is titled "El Pegao," which refers to someone who is "stuck" at a party and doesn't want to leave. The singer describes himself as the life of the party, the one who brings the flavor, and despite not being invited, he's not going anywhere. He's "pegado" to the party, enjoying himself and refusing to leave.
Have you ever felt left out? Jhonny Rivera's "El Pegao" is all about that feeling, but with a hilarious twist! Our guy finds out there's a party happening, and guess what? He wasn't invited! He sings, "hicieron una fiesta ya mí no me invitaron y yo tan buena gente eso sí está muy raro" [they had a party and didn't invite me, and I'm such a good person, that's really weird].
But instead of staying home and sulking, he decides to crash it! He declares, "mejor me cambio y me voy para allá" [I'd better change and go there]. Once he's there, he's not leaving, no matter what! He's the life of the party, the one who brings the flavor, and he's ready to dance all night. Even when people give him dirty looks for eating all the pork rinds, he's like, "cuál es el problema para eso lo compraron" [what's the problem, they bought it for that]. He's a total party animal, and it's super funny to hear him insist, "yo de aquí ya no me voy" [I'm not leaving here now]!