The sun, the surf, the shocking amount of spring-break skin! The producers of MTV's seminal reality series ''The Real World'' take the genre to a new medium with The Real Cancun, a bawdy big-screen cocktail that didn't tempt moviegoers but goes down easy enough at home, courtesy of the well-chosen, almost-too-goofy-to-be-true revelers willing to let their shenanigans be filmed. There are the requisite Überbuff meatheads and party-girl twins among the 16 housemates, but it's the transformation of Alan Taylor from a teetotaling rube into the house's body-shot-slurping hero that gives this otherwise unremarkable fiesta its kick. EXTRAS The deleted scenes showcase the more banal moments, but it's a sin to have left out the ''Cast Insights'' (model-hunk Casey: ''I don't get f---ed up a lot. Like, I do but I don't'').