If reviews of "That's My Boy" make one thing clear, it's this: Adam Sandler's return to hard-R-rated territory is gloriously grotesque. Whether or not that's your cup of tea (or flaming bag of feces, for you "Billy Madison" fans) is another matter entirely.

Sandler shares leading-man duties with recent "Saturday Night Live" expat Andy Samberg in "That's My Boy," a comedy that puts the two in a father/son relationship despite the mere 12-year age gap between the comedians. The goofiness of the film's premise pales in comparison to the gross-out gags and countless cameos found within the movie itself — a fact that has reviewers split down the middle. But the vast majority of "That's My Boy" reviews agree that this is Sandler at his filthiest; a side of the comedian that fans haven't seen in years, which should come as welcome news to those pining for the glory days of Happy Madison and Sandler's early comedy albums.

Keep reading for a sampling of "That's My Boy" reviews:

The Story
"The movie begins at full regression, with the younger version of Sandler's character, Donny Berger, seduced by his Mary Kay Letourneau-like math teacher (Eva Amurri Martino, looking like Amy Fisher). After their tryst is exposed at an assembly with the message 'some have greatness thrust upon them,' Donny montage-morphs into a celebutard with his own book (Head in the Class) and TV movie. Decades later, to pay off the IRS, he's enjoined to engineer a TV reunion featuring the estranged, Xanax-popping, spare-underwear-carrying product of this outrageously inappropriate union, a hedge-fund manager (Andy Samberg) who's changed his name to Todd Peterson (birth name: Han Solo Berger) and is about to marry a possible gold-digger (Leighton Meester) on a tony New England estate." — Ben Kenigsberg, Time Out Chicago

Heartstrings, Hugs and Hurls
"It's my job to offer you that plot summary, and I apologize because it's an icky premise for a comedy. I must also report that 'Boy' gets way pervier — you can't unhear some of the stuff that's involved here. Weirdly, though, there's an undercurrent of sweetness in the film's father/son reconciliation theme. It contrasts surprisingly well with the escalating cascade of gross humor, which could be summed up as: fountain of urine, inappropriate masturbation, nakedness in public and 'What is Vanilla Ice doing in my room?' " — Chris Hewitt, Pioneer Press

Hard-R Territory
" 'That's My Boy' is Sandler's raunchiest movie — its approach to sex is enthusiastic and juvenile and the opposite of the squeamishness of 'Bucky Larson.' Three-ways are had with grandmothers, wedding dresses are defiled, sticky post-masturbatory tissues are flung everywhere and a late twist takes the film into what has to be new territory for a gross-out comedy." — Alison Willmore, Movieline.com

Samberg Unbound
"The truth is, even without pleasant surprises like Vanilla Ice and [Milo] Ventimiglia, I'm not sure I could ever truly hate a movie that features so much of the adorable Andy Samberg, who acts his little heart out as if this were Shakespeare in the Park. Having the past and present 'Saturday Night Live' cast members play father and son was a stroke of genius. I don't know if director Sean Anders (who co-wrote the deliriously stupid 'Hot Tub Time Machine') was directly responsible, but he certainly was lucky. Samberg plays Todd as a sort of manchild, as fresh as a daisy, as affable as a puppy. Compared to Sandler's Donny, who needs to be bathed, then fumigated, he's practically dewy. His chin dimple has never seemed so akin to a baby's bottom." — Mary Pols, Time

Final Verdict
"The gauge to any humor is whether or not it tickles your fragile funny bone, and in this regard, 'That's My Boy' succeeds. It's a gangly guilty pleasure experience that makes you feel foul for enjoying its obvious, out of control bravado. Sandler is terrific as the tacky center of attention and even with a bloated belly and bad mat of monkey fur hair-do, he's winning. Yes, some of the jokes fall very flat indeed and there's more F-bombs than in a Scorsese gangster flick, but the end result is genuine. Indeed, Sandler, more than anyone, has been guilty of turning the big screen comedy into a premise with no pay-off. 'That's My Boy' promises things you hope it won't deliver. When it does, you'll be ashamed of your reaction, but happy that Sandler has returned to his randy roots." — Bill Gibron, Pop Matters

Tell us what you think of "That's My Boy" in the comments section below!

Check out everything we've got on "That's My Boy."

For breaking news, celebrity columns, humor and more — updated around the clock — visit MTVMoviesBlog.com.