“Don’t know when I’ve seen such a lovely wedding. But I always cry. Don’t know why it is, but I always cry,” says Louella Soames in a famous speech from the play “Our Town.”

Here’s why you cry, Louella.

Weddings are utterly depressing affairs, whether you’re trapped in the bowels of introspection — What is love? Baby, don’t hurt me! Don’t hurt me no more! — or surrendering your best friend to a louse she met at trivia night. Thinking about all the mechanical grins, airtight itineraries and grayscale beef has me sobbing right now. Lovely they ain’t.

And yet movies and TV shows are obsessed with nuptials for all the wrong reasons. Hollywood thinks weddings are the perfect blank canvas for goofball comedy, like Owen Wilson and Vince Vaughn arriving at the ceremonies uninvited in “Wedding Crashers,” or Zac Efron and Adam DeVine oafishly hunting for plus-ones in “Mike and Dave Need Wedding Dates.” Want blissful wedded romance? Look to any Julia Roberts movie from the ’90s (save for “The Pelican Brief”). Even being abandoned at the altar can lead to precious new beginnings. Just ask “Sex and the City’s” Carrie Bradshaw.

But never in the vast pantheon of wedding fiction have I heard as truthful and excoriating a critique as this:

“Let’s spend thousands of dollars to honor you for making one f - - king decision that frankly has no bearing on me whatsoever, except that it somehow enshrines the officially nonexistent role I’ll play in your life from now on.”

Ouch. That’s from Joshua Harmon’s vicious new comedy “Significant Other,” which opened on Broadway on Thursday night. The phenomenal play zeroes in on the elusiveness of modern love, and the pesky way a pal’s wedding can make you feel like a doomed spinster cat lady. Doesn’t sound like Meryl Streep riding a donkey at the end of “Mamma Mia!,” does it?

Jordan (Gideon Glick, giving one the finest performances of the season) starts off with three single girlfriends with whom he gabs and goes clubbing. But, one by one, they get engaged and plan extravagant destination weekends in faraway cities. Sure, he’s invited, but whom to bring? His only boyfriend prospect is a co-worker with whom he can barely muster a “Hi.” As couples pair off on the reception dance floor, Jordan stands on the periphery in sad contemplation of his own loveless life.

The premise seems like a drag, but the play is remarkably hilarious, sharp and sweet. Its beauty comes, in part, from terrific performances from Glick, Lindsay Mendez, Rebecca Naomi Jones, Sas Goldberg and the indomitable Barbara Barrie — but also from the intense relatability that other plays this season such as “The Encounter” and “Heisenberg” lack completely.

Although crippling loneliness transcends identity, the message here is, admittedly, most relatable for gay men.

Gay marriage was only legalized nationally in 2015. And while straight couples have had millennia of practice, the art of binding courtship is new to many gay men, who long thought such a life wasn’t even on the table for them. Hence the feelings at a wedding of frustration and confusion that a cynical observer might consider selfish or bitter. Assimilation is harder than it looks.

But at the performance I attended, Jordan’s powerful takedown of this archaic tradition was met with a smattering of cheers from all genders and ages. In the dark, it’s easier for the normally silent majority to admit the truth: Weddings suck.