VENENO ("poison") is LOUTA describing someone he cannot quit even though he knows he is just one more trophy. The hook says it straight: "Solo por necesidad a uno más enamorás, pa' tu colección", you make one more guy fall for you only out of need, for your collection, and "si no hay conexión, no te preocupás", if there's no connection, you don't worry, "solo es uno más", he's just one more.
Notice the Argentine Spanish: enamorás, preocupás, mirás, tenés and sos are the voseo forms that Argentina uses instead of tú. The verse is a list of things she should stop doing ("No me aprietes la cara, no me peines las cejas", don't squeeze my face, don't comb my eyebrows) and a confession that one look and a laugh from her turn him to gold. Then the chorus lands: "Poderoso veneno, me deja tirado... cansado", a powerful poison that leaves him wrecked and worn out.
The second verse gets stranger and funnier. He says he gets empalagado (sick of too much sweetness) on his own ideas and looks like a centipede, and ends with "El mundo es ciego, pero yo ahora veo lo que no ves", the world is blind, but now I see what you don't. In the background a voice keeps repeating "Yo no quiero morirme de amor": I don't want to die of love.