Our sources say they all had some amazing conversations and laughs during the dinner, which had a menu with the band's name on it. We're told everyone was glad to be back under the same roof all these years later.
BTW, we've confirmed the rumors the group is featured on a song for the upcoming movie, "Trolls Band Together" ... which focuses on Justin Timberlake's character reuniting with his 4 brothers who were all part of a boy band in the past -- pretty meta.
So there might not be an album, but at least a new song is coming soon!
Tuesday night's appearance was the first time they've all been at the VMAs together since 2013. As we reported, a source connected to the group told us they wouldn't be performing but would only be presenting an award ... which ended up going to Taylor Swift.
We covered it all on the latest episode of The TMZ Podcast, available on all podcast platforms.