Jimmy (Chris Geere) and Gretchen (Aya Cash) celebrating the power of love (and also lying) in You’re the Worst. Photo: Byron Cohen/FX

You’re the Worst, a series that asks whether two people allergic to commitment can actually commit to each other, begins its fifth and final season by leaving those two people completely out of the picture.

The entire first half of “The Intransigence of Love,” which premieres January 9 on FXX, follows the developing 1990s-era chemistry between a cinephile video clerk and a stunning film geek who bond over a shared affinity for art-house movies. For about 13 minutes, the two protagonists of the show, Jimmy (Chris Geere) and Gretchen (Aya Cash), do not appear at all. It’s like someone replaced You’re the Worst with a never-before-seen 1997 Miramax production directed by Kevin Smith.

For obvious reasons, this is confusing. But as the episode progresses and Jimmy and Gretchen eventually appear, it becomes clear that this narrative misdirect serves a comedic and thematic purpose. You’re the Worst, which has spent four seasons subverting practically every idealized notion about love, wants to focus its last 13 episodes even more pointedly on whether it’s possible for two dysfunctional assholes to form a functional, less asshole-ish union. It does so by tracing the path toward the ultimate relationship goal: marriage.

Yes, Jimmy, the self-involved writer who first met Gretchen after being kicked out of a wedding, and Gretchen, the dysfunctional PR pro who first met Jimmy while dashing out of that same wedding with a stolen gift, are planning to get hitched. Every half-hour installment of season five inches closer to their big day, while hinting pretty loudly that there’s no chance that day will ever come, either because of their ongoing prenuptial acts of self-sabotage or because of events teased in increasingly revealing flash-forwards. For one last frequently-crude-yet-still-warmhearted time, You’re the Worst asks the question: Is it possible for two flawed, narcissistic individuals to truly care for each other? In its brilliant finale, it actually answers that question, in a way that’s both surprising and utterly in keeping with the cynicism that continues to make You’re the Worst such an addictively bitter stiff drink.

In the process of answering that question, You’re the Worst also does what it always does: relish in presenting the bad decisions of a bunch of seriously messed-up dummies. There are a few times this season when the comedy sinks a little too low-brow; in one episode, Gretchen forces Jimmy to — I’m sorry, but this is what happened! — eat his own cum in order to prove his devotion to her. At that moment, I thought, “Wow, Gretchen. You’ve cheated, lied, and gotten underage kids drunk, then played a very disturbing game of Truth or Dare with them. But this is gross even for you.” Still, when You’re the Worst fully assembles its ensemble of degenerates — that includes Gretchen’s best friend and horndog-in-crime Lindsay (Kether Donohue); Jimmy’s BFF, the earnest Iraq War veteran Edgar (Desmin Borges); Paul (Allan McLeod), Lindsay’s ex-husband and front-runner for the Blandest Guy on the Planet Award; Lindsay’s selfish sister Becca (Janet Varney); and Becca’s deliciously reprehensible husband Vernon (Todd Robert Anderson) — the show hums with squirm-inducing hilarity.

All of these actors have played these parts long enough to know exactly how to hit the right notes and find the proper grooves. They’re all experts at being unbearable but just funny enough to make you root for them. Geere, as always, utters nearly every statement with a British “Are you mad?” incredulity that is endearing in its smugness. And so help me, I have come to absolutely adore Anderson’s take on Vernon, a man I would loathe to his trash juice-drinking core if I encountered him in real life, but who cracks me up every time he says something idiotic and/or ill-advised, which is pretty much every time he speaks. “I could have been married to Téa Leoni,” he reminds his wife Becca with intense and complete seriousness. When Becca notes that he merely stood in line with her at a Jamba Juice on one occasion, he indignantly retorts: “She said, ‘Nice jacket.’ Who knows where it could have gone?” Anyway, my point is: please make a You’re the Worst spinoff in which Vernon actually does marry Téa Leoni, then constantly tries to pop up in random cameos on Madam Secretary. Thanks in advance, FXX.

Donohue, who highlights Lindsay’s vulnerability and nitwit tendencies with constant commitment, and Borges, who has become a more confident version of Edgar, are very good, too. But the heaviest lifting falls to Cash, who continues to credibly take Gretchen from super-blasé to the brink of a breakdown in a quick blink. As established in previous seasons, Gretchen suffers from clinical depression, and to You’re the Worst’s credit, it does not let us forget that nor does it allow Gretchen and Jimmy to sweep that fact under the rug as they prepare to (potentially) spend the rest of their lives together.

The entire final season of You’re the Worst, and especially its last episode, feature callbacks to traditions and moments in the show’s history, from Sunday Funday to yet another cameo from singer Ben Folds. It’s a fitting send-off for a show that is ending at the right time; truly, there’s only so much more deplorable behavior from these Californians that we could happily continue to tolerate. What ultimately makes this season so meaningful and smart is its insistence on confronting the underlying, more dramatic issues with which the series has always wrestled.

In a pivotal scene near the end of the season, Edgar says to Jimmy, regarding his relationship with Gretchen: “You love each other, but that’s not the same thing as being good for each other.” This is something no one wants to hear from a friend, especially right before their wedding. But it’s also the kind of thing that most people don’t say to their friends or themselves, even when they probably do need to reflect on that.

Everybody covets the ’90s rom-com version of romantic bliss. You’re the Worst suggests, with equal parts candor and sleazy absurdity, that that’s not possible, while not ruling out the possibility for achieving some sort of happiness. It does that while totally hammered, and with a middle finger lifted triumphantly to the sky.

In other words, this rebellious comedy stays true to itself, to the very, very end.