*NSYNC’s Joey Fatone, Backstreet Boys members AJ McLean and Nick Carter and Boyz II Men’s Wanya Morris are teaming up for a nostalgic four-night engagement at The Venetian Resort Las Vegas in August.

The musicians will unite in the intimate Sands Showroom for “The After Party,” an interactive show which will see the crooners perform each other’s hits with a live band, rock their loved choreography, explore other genres, bring in surprise guests and share untold stories from their time on the road.

“We wanted to do something with the idea of the Rat Pack meets the Pop age now — different artists coming together and doing a show that’s fun, but also takes you through a bit of history,” Fatone, 44, tells Variety. “But it organically also turned into more of a celebration of our bands and a homage to pop culture.”

“You’re going to see these guys and these groups in a light you’ve never seen them in before,” Fatone adds.

The news comes just weeks after McLean, Carter, Fatone and his bandmate Lance Bass hit the stage at The Grove in Los Angeles to debut their collaborative group “Back-Sync.” Earlier in June, McLean also teamed up with *NSYNC’s Chris Kirkpatrick and 98 Degrees’ Jeff Timmons for a Las Vegas fundraiser benefiting the Victoria’s Voice Foundation.

Fatone says “The After Party” was in the works well before Back-Sync, partly inspired by his “Joey Fatone and Friends” concerts at the 2019 Epcot International Food and Wine Festival. The shows saw him perform alongside musicians including Kirkpatrick, Ryan Cabrera and Boyz II Men’s Nathan Morris.

Both Fatone and Carter were further inspired after competing on “The Masked Singer.” “It was so fun doing songs and covers, we thought, ‘Why not integrate that into something we can do with a show?’” Fatone says, noting that all four musicians have also competed on “Dancing With the Stars.” “We’re getting our setlist together right now and coming up with a lot of crazy, interesting ideas.”

“We’ve had so much fun putting this show together,” adds McLean. “I can’t wait to share it with the fans. I promise an incredible night of wild surprises.”

Those surprises will include musical guests, like other boy banders. Timmons could be a likely contender given he resides in Las Vegas, while his bandmate Nick Lachey shares “The Masked Singer” and “Dancing With the Stars” connections with Fatone and co.

Another possibility could be New Kids on the Block’s Joey McIntyre, who kicks off his own Las Vegas engagement, with Debbie Gibson, in the same theater just days after “The After Party.” And while Bass isn’t part of the lineup due to prior commitments, Fatone doesn’t rule him out as a guest.

“There’ll be a bunch of guests coming in and out, which is how it has the feel of the Rat Pack,” Fatone says. “People can just show up and do a song.”

But it’s not just pop stars who will cameo, with Fatone teasing one guest is “in a very heavy, hardcore rock realm.”

“Maybe you’ll even see Wanya Morris come out and sing a rock song — that’s what’s great about this show,” Fatone says. “We might throw in tunes that people have never seen us sing before.”

Carter, for one, is already practicing his rock moves, having jumped on a table and performed Metallica’s “Enter Sandman” at the wedding of Live Nation’s SVP Las Vegas Residencies, Amanda Moore, over the weekend.

The show’s set list will change nightly and in addition to musical performances, the singers will share tales from their time on the road and possibly take audience questions.

“There’s going to be a lot of interesting stories that we don’t normally talk about, as far as touring and dealing with funny, interesting things that happened to us,” says Fatone, who hopes further shows will be added. “There’s so many parallels, especially between me and the Backstreet Boys’ universe, so there’ll be a lot of comparisons.”

Other ideas the stars are tossing around include taking spontaneous song requests and showcasing Morris’ vocals by getting him to sing jingles in a sexy way. “It’s pretty much going to be a different show every time,” Fatone says.

The shows run from August 19 – 22 and are being co-produced by Mulvi Group, SPI Entertainment and Live Nation. Tickets start at $65 and will go on sale to the general public on Saturday, July 10 at 10 a.m. PT via Ticketmaster.com.

Artist fan club members will receive access to a pre-sale beginning Thursday, July 8 at 10 a.m. PT, while Grazie Rewards club members and Live Nation and SPI Entertainment customers will gain access to a pre-sale beginning Friday, July 9 at 10 a.m. PT.

A limited number of VIP Sound Check Experiences will also be available.

As for what the foursome might call their collaboration, Fatone’s open to ideas. “Men-Sync Boys? Boyz Sync Back? Who knows!”