On a recent Saturday afternoon, Park Slope’s Kings Beer Hall was fêting no fewer than five 1-year-olds’ birthdays. The long, wooden tables in the cavernous space were covered in Mickey Mouse tablecloths, party hats, gluten-free cupcakes and pitcher upon pitcher of German beer.

“We’re regular customers here — we come almost every day,” says party host and Flatbush resident Alex Lovato, 29, whose son, Dante, was celebrating his first birthday. Lovato, and his wife, Carol Rivera, 28, always knew they’d throw Dante’s first birthday at the beer bar, where kids can play arcade games while the parents sip pilsners. “It’s fun for everyone,” say Lovato, who works at a flower boutique. “We get to enjoy ourselves.”

More spacious than having people over to a cramped apartment, and cheaper than renting out a children’s play space, breweries and beer halls have become popular among bougie, outer-borough parents celebrating their tots’ milestones.

“We have at least one toddler birthday party a weekend, if not more,” Kings events manager Miranda Gonzalez tells The Post.

The parties are inexpensive, simple and fun for parents, who typically pay for or bring in their own food, and have the option of picking up guests’ bar tabs, yet rarely have to pay for the space itself. But for customers who just want a chance to unwind and have a beer without dodging rowdy tots, the childish atmosphere can be a bit of a turnoff.

At Kings, Los Angeles visitor Ashley Fontenot was a little shaken by the mix of tipsy parents and crawling children as she sat at the bar, waiting for a friend who was attending one of the parties.

“It feels almost taboo, walking in and having a bunch of alcohol and babies,” says the 39-year-old who works in graphic design. “It’s weird to see little kids running around, and I’m sitting here having a prosecco.”

Other parties aren’t so kid-forward.

‘It’s weird to see little kids running around, and I’m sitting here having a prosecco.’

When Lauren Turner’s daughter, Sloane, turned 1, Turner threw her a party at the Hop Shop, in Brooklyn’s Columbia Street waterfront district.

The 33-year-old social worker set up a playpen and ball pit for the kids in the back, while the parents chatted and sipped local IPAs from the tap room. The kids had plenty of fun crawling around, she says, but “the party was definitely more for adults.”

Hosting Sloane’s bash at the boozy hangout was a no-brainer: Paying for friends’ beers was cheaper than renting out an event space, and the free-flowing alcohol meant parents had a great time.

“It was a very relaxed and easy way to throw a party,” Turner says.

But as easy as the decision is for some hip parents, balancing fun-seeking adults with hordes of kids can be tough for brewers.

“It’s a little bit of a double-edged sword for us,” says Threes Brewing co-founder Joshua Stylman. “We really want to make sure people feel welcome, but we don’t want it to become a turnoff for adults.”

When the Gowanus brewery, taproom and backyard opened in 2014, the owners thought long and hard about how to handle children. “We had heard some [horror] stories about other places,” he says.

So they set some strict ground rules: Children must leave the brewery by 7 p.m. and can never be left unattended. Balloons, cakes and other festive touches are all fine by Stylman, as long as the parents call ahead to clear it — and make sure that strollers aren’t blocking anyone’s path.

First birthday parties are usually a hit — the babies are happy to be out, while the parents are grateful to have a few beers with friends. As the kids get older and more active, it gets trickier.

“I don’t think it’s a great place to have 20 5-year-olds,” he says.

Despite the precautions, the brewery still gets complaints about the commotion from child-free customers. “That’s why we’re pretty stringent about our policy,” he says.

Kings Beer Hall had to tweak its own policy in December after safety became an issue.

“There’s a tendency, when you’re drinking and having a good time, to relax a little bit,” says Gonzalez. “That was trickling into relaxing to the point of not keeping an eye on your kid, which turned into, if your kid was one inch to the left, he would’ve lost his eye with a pool stick. It just became kind of a liability.”

The doors now close to anyone under 21 at 6 p.m. on weekdays and 3 p.m. on weekends, and the hall put together a set of guidelines, including discouraging rude behavior that’s previously been an issue. They include no running, no climbing on furniture, no changing diapers outside of the bathroom and no more than three children per adult.

The beer hall posted the rules online and on its doors and windows, and the neighborhood group Park Slope Parents sent out a newsletter reminding their readers to keep an eye on their kids at bars. Still, says Gonzalez, “we got a lot of pushback. People were like, well, I did this before.”

Still, says Gonzalez, “[The parties are] fairly important for the survival of our space, because we’re in a residential area.”

‘We really want to make sure people feel welcome, but we don’t want it to become a turnoff for adults.’

Kiddie celebrations are a big draw for Staten Island brewery Flagship, too. “At this point, the majority of parties thrown at Flagship are first birthday parties,” says event director Tricia Sykes.

She says they don’t get many complaints about the crawling, cooing kids, and party participants are courteous to non-partygoers.

“People who have parties at breweries are generally chill people,” says Sykes.

But for all the “chill” parents, there are others who can’t stand the idea of kids birthday parties at bars and breweries.

Robert Holst says he adores his three young kids but would never throw them a party at a watering hole. “I go to the bar with my friends, or to have a beer after work,” says the 44-year-old Staten Island electrician. “It’s so that I can take a break — I’m not going so I can listen to your kids.” He says that he can’t stand arriving at his favorite beer spot, only to find all the seats taken by children, with toddlers crawling around on the floor.

“It’s crazy,” he says. “Beer is for adults, not kids.” He says that luckily, he’s never been invited to such a party.

Some Brooklyn bars opt out of the kiddie biz altogether. Clinton Hill’s Hot Bird got serious flak when it banned children in 2014, after its large outdoor area became overrun with strollers. At the time, a bartender told The Post: “There were too many people bringing small children here.” And Circa Brewing, a new Downtown Brooklyn hall, says it doesn’t allow baby birthday bashes.

Sam Dyer, a 36-year-old mom of one, wouldn’t be suprised if more places decide against baby bashes.

The Carroll Gardens resident says that she gets why a brewery is such an appealing location for a party — “It’s cheaper than doing it at Kidville,” she says, of the children’s space which charges $695 ($995 for deluxe) for a 90-minute party at its Carroll Gardens location — but she’s also seen kiddie culture transform once-hip spots.

She used to frequent a local beer hall, Buschenschank, but noticed that the average occupant age kept getting younger. It closed in 2016.

“It sort of seemed like it became overrun by kids’ birthday parties,” she says. Other kid-party spots could face a similar fate. She says skeptically: “It may not be such a long-lived trend after all.”