Zac Efron shows off first teaser trailer of Baywatch and FYI, he's topless most of the time... This image appears in the gallery:This Week's MUST-SEE Photos From The World Of Music 20. Zac Efron shows off first teaser trailer of Baywatch and FYI, he's topless most of the time... ... which is completely okay with us. Picture: Twitter 29 images See the full gallery: This Week's MUST-SEE Photos From The World Of Music