Pistear is a colloquial and somewhat informal verb, primarily used in Mexico, that means "to party" or, more specifically, "to drink alcohol."
In the song, the lyrics "Ella quiere beber, ella quiere pistear" (She wants to drink, she wants to party/drink) highlight a common social activity. It's an interesting word because it's not the standard verb for drinking (like beber or tomar), making it a more unique and culturally specific term that adds flavor to the lyrics and offers insight into regional Spanish slang.
Armenta and Manuel Turizo's "Feliz Año Nuevo" is a super relatable track about that post-breakup ache, especially around the holidays. The singer is clearly still reeling, admitting, "Esta llamada solo es un pretexto / Pa' oírte de nuevo" [This call is just an excuse / To hear you again]. His family keeps asking about his ex, and he doesn't know what to say, making Christmas not special at all. He's dreading February 14th, knowing he'll be "Más solo que un perro" [More alone than a dog].
He's even worried about seeing her with someone new in the summer, and you can feel his pain when he sings, "Ando bien dolido / Tachando los días que no he estado contigo" [I'm really hurting / Crossing off the days I haven't been with you]. He's stuck on a calendar that reminds him his birthday will be sad. It's a mix of emotions: "A veces te odio y a veces te extraño" [Sometimes I hate you and sometimes I miss you]. Even though time passes, he can't get over her, so all he can do is wish her a "Feliz año nuevo" [Happy New Year]. Manuel Turizo jumps in, adding to the regret, acknowledging he "pagé mal" [treated her badly] and that the harsh reality hits with the sunrise. It's a raw look at heartbreak and regret, especially when everyone else is celebrating.