I was listening to "Despacito", and it seems that both singers use /v/ (Fonsi at 0:42 with his mouth visible, DY at 1:00) as an allophone of native /β/ (still used, e.g Fonsi, 1:52).
Most Spanish speakers I know only pronounce /β/ labiodentally when smiling through rapid speech (on which occasion they'd also pronounce /p/ and /m/ labiodentally).
Is this standard in Puerto Rican Spanish?
Found in the abstract of a presentation (Exford 2016):
Native Spanish speaking college students in San Juan, Puerto Rico that are bilingual in English to some degree are interviewed to perform audio-recorded speaking tasks. Results show that labiodentals are undoubtedly produced for Spanish phoneme /b/, but are done so exclusively for orthographic v. On average, grapheme v was pronounced as a labiodental 56% of the time. Grapheme b was never pronounced as a labiodental. In addition to orthography, the results speculate that labiodentals are also conditioned by speech style or formality, as labiodental frequency reduced when tasks became more informal.
So [v] for /b/ spelled v does seem fairly common in Puerto Rican Spanish. The author suggests it may be an effect of hypercorrection.
My father was born in Puerto Rico, and due to my initial informal education in the language I actually thought it was a hard V sound and spelled it accordingly (saves), and is how my family (and myself) tend to pronounce it to this day. It might be more of a rural thing though, as my father's family comes from a small farm on the coast.
