Yes, again already. Get used to it. For the next fifteen years (and counting), nearly every single he releases will go #1. Not all of them, of course, are created equal.
Which makes it sound like I think this one is bad. I don't, quite: there are some quite good things about it, but it's a mismatch of singer, style and song. Iglesias is still singing like a rock singer here, belting grittily in a thin, static register, the audio equivalent of those Rob Liefeld comic books where everyone scowls grimly so much that it looks like they're constipated. He has not yet learned what his voice can do — and, more to the point, what it can't. If he were the singer he thinks he is, if he were Julio Iglesias or Luis Miguel or even Cristian Castro, he'd be able to overcome the repetitive up-and-down-the-scale of the song's melody (if the song's melody were plotted on a graph, it'd be as regular as a heartbeat, but not as warm), but as it is he doesn't even emote, he just groans.
Which is too bad; because the song, outside of the grinding melodic mechanics, is actually pretty good. I won't be so condescending as to translate the title (obvious Latinates are obvious), but the first line of the chorus makes the crucial distinction "casi" ("almost") -- settle down, priests and mothers, he's not saying sex is a religious experience, just that it's like one. Except that, three lines later, he says it straight: "es un experiencia religiosa" ("it is a" etc). But pay no attention to the flip-flopping semantics: the real highlight of the chorus is the sly rhyme "besar la boca tuya merece un aleluya" ("kissing your mouth deserves a hallelujah" — it's, sigh, better in Spanish), the kind of wordplay that died out in English-language pop with Ira Gershwin.
The requisite gospel choir comes in the for the last couple of choruses, which only further underscores how far this is from anything actually religious — Latin Pop audiences are so overwhelmingly Catholic that the gospel choir, a trope imported from American soul and rock music, is a signifier of generalized, and international, ambition rather than anything bone-deep to the culture. The hair-metal guitar solo that wails just after gives it away: this is (not very good) international pop, not particularly Latin in any way. (Enter Boyzone's 1997 cover "Mystical Experience," a pretty direct translation and even less bearable.)
Enrique will find his voice eventually, and material that's worthy of it. But it'll be a rocky road for a while. Buckle up.