Two miniature horses, Aidan and Pearl, stood on the terrace of a tiny TV studio in SoHo earlier this month on a sweltering evening, one more equine guest than the producers of “Watch What Happens Live With Andy Cohen” anticipated. They were part of a bit for taping the late-night talk show’s 15th anniversary special and, apparently, booking a horse requires also booking it an emotional support horse.

Andy Cohen, the show’s host and creator, brought his two children Ben, 5, and Lucy, 2, to meet the mini horses as producers whispered questions about the surplus. He soon headed back inside to provide emotional support of a different kind for the show’s humans. Gliding effortlessly between posing for photos with guests, including Sonja Morgan, a mainstay of “The Real Housewives of New York” who arrived in a diamond-studded (she said they’re fake) tiara, Cohen listened to instructions from his producers while also recording behind-the-scenes footage for social media.

It was a lot of wrangling, even for Cohen — the core moderator and pot-stirrer of “W.W.H.L.,” the recap show that somehow manages to lure A-list celebrities like Oprah Winfrey and Jennifer Lawrence to marvel at the antics of the stars in Bravo’s ever-expanding reality universe. Five nights a week, viewers can see Oscar-winners re-enact scenes from “Real Housewives of Salt Lake City”; so-called Bravo-lebrities dish about just-aired dirty laundry; or Cohen and Hillary Clinton drink from a shotski, a ski with shot glasses glued to it that allows multiple people to simultaneously knock one back.

The show, and the reality TV universe it obsesses over, delight in outrageous behavior that is under scrutiny as Bravo currently faces multiple lawsuits. Former cast members from several series accused the network and producers of racial discrimination, running an alcohol-fueled workplace and failing to respond properly to reports of harassment and assault. After an internal investigation, the network said it cleared Cohen of claims made against him by two former Housewives, including those detailed in a lawsuit from a former cast member who said the show’s producers had encouraged her to relapse to boost ratings. Cohen also apologized for sending one former cast member a video message that she said constituted sexual harassment.

Many of the regular bits on “W.W.H.L.” are related to alcohol: Each episode begins with Cohen revealing a word of the night for viewers to drink to every time it’s uttered; each ends with him encouraging the audience to drink responsibly. Regardless, Cohen and his team maintained that drinking on set was optional and not essential to the show.

“Fun is the culture at ‘W.W.H.L.,’” Cohen said. “Some guests choose to have a cocktail, others don’t — there’s absolutely no pressure.”

Beginning in 2009 as a web series shot in a studio without air conditioning, “Watch What Happens Live With Andy Cohen” has grown into cable TV’s highest-rated late-night talk show, one that thrusts Bravo’s reality TV shows into the forefront of pop culture. We spoke with Cohen and the show’s producers and went behind the scenes to learn how.

It Started With Andy’s Emails

As Bravo’s vice president of original programming back in 2004, Cohen regularly emailed what he called “dishy reports” to his bosses about the shows they were producing. He turned those into a blog, and as the posts became popular, Cohen began making guest appearances on network morning shows as a television pundit.

In 2009, Michael Davies, a Bravo producer, saw Cohen host a reunion show for “Flipping Out” and offered him a studio and a tiny budget to start a show rehashing “Top Chef” and “Project Runway” at midnight, after those series aired new episodes.

The idea was that “W.W.H.L.” would mimic the conversations happening in the heyday of Twitter, the platform now known as X, with fans sharing their opinions on shows they’d just watched.

“It was really centered around Andy’s sensibilities and point of view since he knew the shows inside and out and knew what fans wanted to hear more about,” said Deirdre Connolly, the executive producer of “W.W.H.L.” since it began.

As audience members and Bravo-lebrities filed into the SoHo studio for the anniversary taping, Cohen exercised the same attention to the show’s details. He asked producers for their thoughts on the best way to gently ask “Real Housewives of Atlanta” returnee Porsha Williams about her relationship status. (She filed for divorce as the current season began filming and it is still in production.) When producers alerted him that Phaedra Parks had brought the “Love Island” star Ekin-Su Culculoglu as her plus-one, Cohen double-checked the exact phrasing of Parks’s infamous “Traitors” tagline, “Oh lord, sweet baby Jesus, not Ekin-Su,” so that he could use it on air.

Leaning Into the Messiness

Almost every episode of “W.W.H.L.” guarantees unpredictability — whether through Cohen’s probing questions or games designed to put guests on the hot seat.

Cohen pointed to a 2011 episode that became a favorite for him and viewers, though he initially feared that the show had veered off the rails.

When the actresses Regina King and Jackée Harry, castmates on the 1980s TV comedy “227” long before King became a film star, arrived to the “W.W.H.L.” studio, it was obvious they had been drinking. Cohen initially panicked.

“I just remember during the first commercial break, in my mind, I felt like I didn’t have control over the show,” Cohen said. “Deirdre said to me in my ear, ‘This is amazing — we’re trending number one worldwide on Twitter.’”

The bawdy and mildly chaotic episode taught Cohen a lesson: “Always lean into whatever is happening, even if it appears a little nasty or especially if it appears a little messy,” he said.

Since then, Cohen has left space for messiness to run rampant — clips online show how unguarded guests can be, with Whoopi Goldberg teaching Cohen how to roll a joint and Shaquille O’Neal coyly responding to the host’s question about a part of his, err, anatomy.

During the filming of the anniversary episode earlier this month, Morgan (of “The Real Housewives of New York”), the tiara glittering atop her head, became the primary source of messiness. At one point, she walked off the set during a commercial break, angry about …something. Producers tried to coax her back onto the soundstage while Jerry O’Connell, another guest, bet the audience that she wouldn’t return. He lost — but it wasn’t until Cohen himself went to talk to Morgan that she agreed to come back.

When filming resumed moments later, as Cohen tried to introduce a video montage, Morgan interrupted, “I think Andy should be mayor.” Cohen shushed her and during the next commercial break, staffers put a glass of water next to Morgan’s seat.

Interviews Create Headlines

This messiness helps fuel the show’s popularity and relevance outside the network, with Cohen steering conversations that simply wouldn’t fly on other talk shows.

“His unique ability is to go there — one of his trademarks is asking provocative questions,” said Nick Rizzo, a supervising producer on the show. “And what I think he doesn’t get enough credit for is he does an incredible job of also listening to guests and then asking the follow-ups and getting wild confessions as a result.”

John Oliver, the talk show host, political pundit and recurring “W.W.H.L.” guest fueled a week’s worth of internet headlines with an appearance in March. After weighing in on the lengthy divorce arc of two “The Real Housewives of Miami” cast members, Cohen asked if Oliver had had enough of Kate Middleton rumors, amid speculation about her absence from public appearances. Oliver joked that he believed she was dead, and Variety, Business Insider, Vulture, Vanity Fair and Page Six all wrote about his jesting statement.

A-Listers Fawn Over Bravo-lebrities

The show reached a new stratosphere when A-list celebrities started making their way into the clubhouse. Winfrey’s 2013 visit, Cohen said, helped validate the show.

“The fact that she came to our little clubhouse in SoHo and she deemed us important enough, was really, you know, just an incredible moment, personally and professionally,” he said.

Since then, Meryl Streep, Julia Roberts, Jennifer Lopez and 50 Cent have all stopped by Cohen’s clubhouse as part of press tours. But they do so with the understanding that Bravo shows and their stars are the central conversation.

In one recurring segment, “Clubhouse Playhouse,” mainstream stars re-enact scenes from Bravo shows, allowing those moments to reach new viewers via shareable clips. In one of the most popular videos, “Mad Men” stars Jon Hamm and John Slattery took on a scene from Season 10 of “Vanderpump Rules” when cast member James Kennedy memorably called Tom Sandoval “a worm with a mustache,” with Hamm using a British accent.

“I would say once a year I email Deirdre and the team, and say, ‘Can you please remind everybody that we can do anything on this show?’” Cohen said. “And no idea is dumb enough and that we have always pushed the envelope and we need to continue doing it.”