Picheo is a popular slang word from the Caribbean, especially Puerto Rico, that means 'to ignore' or 'brush someone off'. It's a fantastic example of Spanglish, as it comes from the English word 'pitcher' from baseball!
In the song, Omar Courtz sings, 'Yo a veces picheo' (Sometimes I ignore you), describing a situation where he's playing it cool and pretending not to be interested. It's a fun, memorable word that captures a very specific feeling of dodging or ignoring someone, just like a batter dodges a pitch.
Omar Courtz lays out a very specific scene in "LUCES DE COLORES" (Colored Lights). It's all about a hookup that's intense and purely physical, at least from his side. He describes how the woman sets the mood, plugging in colored lights and using a movie as an excuse to get intimate. The connection is so strong that he says, "Mi olor se le queda por más que se ducha" [My scent stays on her no matter how much she showers]. It's a blunt and confident way of saying their time together leaves a mark.
But there's a problem. She keeps asking him to come back, saying "Vuelve" [Come back], and he admits he sometimes ignores her. Why? Because, as he tells her directly, "porque te me envuelves" [because you get attached]. He enjoys their time together, even admitting "Yo sé que no te gusta dormir sola, a mí tampoco" [I know you don't like to sleep alone, me neither], but he's actively pushing back against any emotional connection. The song is a cycle of intense passion followed by him pulling away to keep things from getting serious.