Just in time for Father’s Day weekend, That’s My Boy hit theaters today. And I have absolutely no intention of seeing it. You want some lowbrow laughs with Adam Sandler and Andy Samberg? Fine. You can have them. Personally, I’d rather see a dark comedy starring Robin Williams, written and directed by Bobcat Goldthwait. With Richard Kelly of Donnie Darko fame producing, strangely enough.

In World’s Greatest Dad, Williams plays Lance Clayton, who aspires to be a published author. Not because he enjoys the craft of writing, he just wants the money and adoration that comes with making a best-seller. And if he can help his audience through the pain of the human condition, so much the better. In the meantime, however, Lance is just an under-appreciated — albeit reasonably-liked — high school teacher, helming a poetry class that’s set to be axed unless attendance goes up.

He’s also the father of the title. The title is meant ironically.

His teenaged son is Kyle (Daryl Sabara), and it’s quickly established that the two of them have a very tenuous relationship. A lot of that has to do with Lance, who simply doesn’t understand his son in any way. Then again, that may be a point in Lance’s favor, since Kyle is… how do I put this nicely? I’d like to call him “an irredeemable piece of shit,” but that seems like an insult to perfectly good fertilizer.

Kyle is vindictive, he’s vulgar, he’s dishonest, he’s cowardly, he’s stupid, and he’s impossibly perverted. It’s not an exaggeration to say that he has absolutely zero interest in anything except porn. Oh, and everyone who isn’t like him is “a fag.” I’m not even kidding when I say that I had to wipe the grease off my screen every time he showed up.

Naturally, the contrast between Lance’s milquetoast demeanor and Kyle’s never-ending sleaziness is a huge part of the movie’s humor, not to mention Lance’s escalating emotional stress. Another factor in the latter is Claire Reed (Alexie Gilmore), the adorable art teacher who also works at the same school where Lance teaches and Kyle is on academic probation. Lance and Claire are dating, and it’s simply precious how they call each other cutesy nicknames and sneak in kisses when nobody’s watching, but their relationship is still kinda complicated. They do work together, after all, and being seen in public by staff or students could lead to some very awkward situations.

There’s also the matter of Mike Lane (Henry Simmons), another colleague of Lance and Claire. Not only is he an English teacher who got a story published in the New Yorker on his first try, but he’s a handsome and charming guy who’s going through a rough divorce. So Lance is of course insanely jealous of the guy, especially when he and Claire are seen together. There are a few subtle signs that Claire might be seeing both of them at once, but she’s just honest enough about the whole thing to imply that it might be innocent. Moreover, Lance and Claire never set any rules about seeing other people, though that doesn’t exactly ease his blood pressure any.

So basically, Lance’s life sucks and he’s not nearly tough enough to deal with everything. There are some signs that he’s going to break soon, and there’s no telling what’s going to happen when he finally snaps. But that’s not the movie we’re watching. In fact, this film almost feels like it’s two movies in one.

See, when the first act ends, Kyle finally does his part to make the world a better place: He goes back to the fiery pit from whence he came. Not only does Kyle die, but he quite fittingly dies in an act of autoerotic asphyxiation.

Not content to let his son die such a humiliating and worthy death, he tampers with the scene to make Kyle’s passing look like a more dignified suicide. Lance even marshals up his overlooked writing talents to put “Kyle’s” parting words to paper. Only it works out too well. The suicide note gets leaked out to the school newspaper, the grief over Kyle’s passing is magnified a billion-fold, Lance is suddenly the center of everyone’s sympathy, and things only get further out of control from there. An unrepentant bag of pond scum becomes a saint, and a lie becomes the truth.

Lance himself handles it far more terribly than he lets on. Even though he knows his son was a totally rotten egg, Kyle was still his son all the same. Furthermore, part of why Lance feels so terrible is precisely because he knew so little about his own flesh and blood (though really, what’s there to know?). This naturally leads to even more lying: Everyone starts asking questions about Kyle that Lance doesn’t know how to answer, so he simply remakes his son in his own image. It’s a crappy thing to do, and we can clearly see Lance’s guilt about it, but who needs reality when this particular truth is so godawful?

More than that, the lie actually proves quite beneficial. The suicide note leads students and teachers alike to seize the day and live healthier lives. Lance finally wrote something that deeply affected people, and no one can ever know.

Yet in spite of all this, the film is still a dark comedy. The premise is textbook dramatic irony, as characters act in ways that are only fully understood by one character and the audience. If it ever starts to get repetitive watching students express their love of Kyle, just remember what a shitbag he really was and the scene becomes laugh-out-loud hilarious in context. Additionally, Robin Williams has such a great flair for emotion that it’s funny to watch Lance’s growing trepidation as he keeps digging himself deeper. These two points form the backbone of the comedy through two-thirds of the film, though there are also some quirky moments of lighter comedy relief to great effect.

There are even some moments when Kyle’s death affects Lance in humorously touching and outlandish ways. Sorry, but it’s just weird to see a grown man cry so profusely at the sight of porn magazines.

Ah, but there’s still Andrew (Evan Martin). He looks and sounds like the kind of kid that everyone would pass in the halls. So small, so quiet, and so withdrawn that it’s like he doesn’t exist. I won’t even get started on his broken home. He was the only friend that Kyle ever had in life, and Kyle was the only friend that Andrew ever had. Naturally, it was a very abusive and one-sided friendship, but it was still the closest thing to friendship that either of them ever knew. And then Kyle died.

So now Andrew’s hearing that his only friend really wasn’t a total asshole. That he was capable of thoughts that didn’t have anything to do with anal sex. The only two conclusions for Andrew to reach are either that Kyle was lying or Lance is lying, and it’s hard to tell which would hurt more.

Basically, Andrew is there to fill the much-needed “Ghost of Christmas Past” role. He’s the only character in this movie who’s never played for laughs at any time, and that’s exactly what the character required.

Evan Martin is the unsung hero of the supporting cast, but there are some other good actors to be found here. There’s of course Daryl Sabara, who does a great job with the Kyle role (though I’m not sure if that’s a compliment). Henry Simmons takes what could have been a very stock “rival” role and plays it without ever becoming overly douchey or unlikeable. Mitzi McCall puts in a brief but very nice performance (though her unusual living habits didn’t pay off as I thought they would), and a cameo from Bobcat Goldthwait himself is good for a few chuckles. As for the love interest, I’d say that Alexie Gilmore establishes herself quite nicely as a poor man’s Judy Greer.

With all of that being said, it’s Robin Williams’ movie, as well it should be. With a career that includes such syrupy dreck as Jack, Patch Adams, and Bicentennial Man, it’s easy to forget that he won a fucking Oscar for Good Will Hunting. He was really good in Dead Poets Society as well. Williams has serious dramatic chops, and he uses them to full effect here. But at the same time, he leverages that unique touch of self-degradation and expert comedic timing that could only come from being one of the greatest comedians alive today.

The role is so perfectly suited to Williams’ talents and so uniquely balanced between tragedy and comedy that Williams is the only man who could ever have played this role. To wit: When Lance finally does threaten to stab Kyle in the face, it’s done with such subtlety and desperation that it somehow becomes funny and scary at the same time. There’s not another actor in the world who could deliver that line like Williams does, I’m sure of it.

Of course, it helps that the screenplay is incredibly sharp. The humor works, the drama works, the symbolism is very well-utilized, and the movie is constantly structured in a way that keeps the audience guessing. You may have seen a thousand movies in which the main character keeps a terrible secret, but I can guarantee you’ve never seen the scenario play out in such a satisfying and heartwarming way.

I’d also add that the music does a lot to keep the film humorous. The soundtrack is filled with upbeat standards, many of which tie in to what’s happening on the screen. So the music is funny because it contrasts against what’s happening, and also because it comments ironically on the action.

World’s Greatest Dad is an underappreciated gem. Robin Williams’ performance alone makes this worth seeing, but it helps that the screenplay and the direction are this damn good. It’s a cleverly-made film that’s funny, tragic, and heartfelt in all the right ways, though I’ll grant that its complicated brand of sickly ironic humor might go over quite a few heads.

If you’re not afraid of some conflicting emotions to go with your comedy, I can’t recommend the film highly enough. Otherwise… well, Adam Sandler has a film out right now.