Happy Madison Productions strikes again with this unremittingly raunchy, crude, groan-inducing so-called comedy that also tries—unsuccessfully—to wring some sentiment out its lame premise at the close. Though being released on the Father’s Day weekend, as penned by David Caspe “That’s My Boy,” which tries to wring laughs from child abuse at the start and from incest at the close, is about as big an insult to fatherhood as one could imagine.

Adam Sandler, once again stumbling through a movie without attempting anything remotely resembling acting (but doing one of the annoyingly scratchy voices he considers characterization), plays one Donny Brewster. He’s the ragged, has-been adult version of a kid (Justin Weaver in the dreadful opening reel) who got his teacher (Eva Amurri Martino) pregnant and rode a wave of adolescent notoriety to flame-out fame while she was sent to the slammer for thirty years. He also raised—very badly—their son Han Solo, who fled home at eighteen and disappeared completely. Now being threatened with jail himself for failing to pay taxes, Donny discovers that his boy, who’s changed his name to Todd Peterson (Andy Samberg), is a rich investment guru about to wed beautiful Jamie (Leighton Meester). So he crashes the kid’s pre-nuptial festivities, initially to get him to visit his mom in prison for a reunion on a crass “reality” TV show that will get him the cash he needs, but in the process simply wanting to reconnect with his son.

It’s almost impossible to catalogue the depths to which “That’s My Boy” sinks in its desperate bid to elicit laughs from the yahoos who still think that Sandler’s lazy shtick is at all amusing. We get and endless stream of blunt sexual jokes, including countless gags about masturbation and multiple scenes involving vomiting and urination. There are fat jokes and drug jokes aplenty, and heaping helpings of slapstick violence besides. The whole ugly business makes the early Farrelly brothers look like choirboys.

The movie repeats most of Sandler’s usual habits. It serves as a vehicle for lots of his buddies: Will Forte does his prissy bit as a colleague of Todd’s, and Nick Swardson proves once more that he’s drearily unfunny as Donny’s garbage-pail pal Kenny. Has-beens are trotted out for a mixture of affectionate ribbing and cruel abuse—Tony Orlando as Todd’s slimy boss, Todd Bridges as a fast-food clerk, and especially Vanilla Ice, playing himself as a hopeless relic of his one-hit celebrity. A few established veterans are subjected to embarrassing turns, including James Caan as a pugilist priest and Susan Sarandon as Todd’s more mature mom (though neither suffers the extent of humiliation Al Pacino did in “Jack and Jill”). Luenell is repeatedly employed for queasy laughs as a friendly but obese pole dancer. But the cast members most abominably used as certainly Milo Ventimiglia, who had a brief moment of stardom himself in “Heroes,” who plays Jamie’s super-macho brother Chad, and Peggy Stewart as her randy old grandmother. Both are subjected to material that’s grossly unfunny in both senses.

Then there’s Samberg, who seems intent on following Sandler’s example and not bothering to learn anything about acting before starring in features. His technique is enough for short television sketches, but in the unforgiving environment of a megaplex auditorium his lack of talent is glaringly obvious. He’s certainly not helped by lax direction from Sean Anders, whose instruction to Sandler seems to have been confined to “Do anything you want for as long as you like” (the movie runs unconscionably close to a full two hours), or the over-lit cinematography of Brandon Trost; but he probably wouldn’t look good even if there were a perpetual scrim over the screen.

The only thing that could conceivably have made “That’s My Boy” worse is if Sandler had played both roles. But it’s terrible enough as it is.