Defying a trend toward baffling abstraction in movie titles  “Synecdoche, New York”? “Quantum of Solace”? “The Secret Life of Bees”?  Kevin Smith has given his new opus a name that tells you exactly what it’s about. Literal-mindedness has always been among Mr. Smith’s calling cards. His first film, about clerks, was called “Clerks.” And so it will hardly be shocking that “Zack and Miri Make a Porno” is about two people, named Zack (Seth Rogen) and Miri (Elizabeth Banks), who make what my copy editors would prefer that I call a pornographic movie.

And really, in spite of an avalanche of verbal filth (and a smaller quantum of the visual variety), “Zack and Miri” is not very shocking at all. Mr. Smith has been tinkering with the dirty-mind/soft-heart combination for quite some time, forming a link of sorts between the humanist sexual anarchy of John Waters and the smutty Victorianism of Judd Apatow. He and his characters revel in dialogue that riffs on body parts and bodily fluids, but Mr. Smith’s stories are bathed  metaphorically!  in syrup and schmaltz.

So “Zack and Miri Make a Porno,” in spite of its sometimes tiresome, sometimes amusing lewdness, follows a gee-whiz romantic-comedy formula that would not be out of place on the Disney Channel. Two best friends who have always been in love with each other discover that ... they have always been in love with each other. Granted, this revelation occurs while they are having sex in front of a camera, but it is so sweet and predictable that these potentially tawdry circumstances hardly matter.

Mr. Smith tries, with mixed results, both to rub our faces in the tawdriness and to erase it altogether. The movie wants to insist that pornography is a jolly, innocuous pursuit, but also to take refuge in a sincere, romantic traditionalism that is antithetical to the cynical, often playful sexual ethos of pornography. Mr. Smith is intent on making a love story, which is almost by definition the opposite of the kind of movie Zack and Miri set out to produce.