'NSync Reunites for JC Chasez’s 40th Birthday: Photo, Details!

JC’s 40th… And, if you don’t know now you know…

A post shared by Justin Timberlake (@justintimberlake) on Aug 8, 2016 at 11:05pm PDT

Tearin’ up our hearts! All five members of ’NSync — including Justin Timberlake — reunited for JC Chasez’s 40th birthday in L.A. on Monday, August 8.

The former boy band celebrated the milestone at a small private party at the Nice Guy, a source tells Us Weekly. Around 50 people were in attendance, including Timberlake’s wife, Jessica Biel.

The “Can’t Stop the Feeling” singer, 35, took a snapshot with Chasez, Lance Bass, Joey Fatone and Chris Kirkpatrick to mark the occasion. “JC’s 40th… And, if you don’t know now you know…” he captioned the nostalgia-filled pic, referring to the Notorious B.I.G. song “Juicy.”

Kirkpatrick, 44, shared the photo via Twitter. “Happy 40 son,” he wrote.

’NSync formed in 1997 and disbanded in 2002 after three studio albums. The group made fans swoon with songs such as its debut single, “I Want You Back,” “Bye Bye Bye,” “It’s Gonna Be Me,” “This I Promise You” and “Gone.”

Last year, Fatone, 39, opened up about what it was really like at the height of the band’s success. “Back in the day it was really hard to all go out together at the same time,” he exclusively told Us in November. “Before the show sometimes we had time to go to a mall — [we] just wanted to be kids. I’m kind of glad it’s not that level anymore, because before I couldn’t go anywhere. I wanted to be normal like everybody else.”

The longtime pals previously reunited during the 2013 MTV Video Music Awards. Timberlake, who was honored with the Michael Jackson Video Vanguard Award, included them in his medley performance. The set included some of his greatest solo hits, such as “Sexy Back,” “Cry Me a River” and “My Love.” His former bandmates then joined in for a rendition of “Bye Bye Bye” and “Girlfriend.”

The five musicians have stayed cordial over the years but have had a few bumps in the road. As Us exclusively revealed, Bass, 37, Kirkpatrick, Chasez and Fatone were initially “upset” that Timberlake didn’t include more ’NSync tunes in his VMA performance. Additionally, no members attended Timberlake and Biel’s 2012 wedding.