Sisqó and Mýa Reuniting For 1st Collab In 25 Years

Sisqó costarred on Mýa's debut single "It's All About Me" all the way back in 1997 -- and the two R&B forces are now combining their talents again for a long overdue sequel ... TMZ Hip Hop has learned.

Sisqó's team tells us he and Mýa have always kept a strong rapport on social media, and when seeing each other on the road.

Fans have been asking for a follow-up track for ages, and Sisqó and Mýa bowed to popular demand. They snapped a pic in the studio and confirmed the record is hot off the presses and should be dropping soon on Sisqó's new album!!!

They're often booked on the same R&B circuits -- they have a big concert this September -- and are known to surprise the crowd with a performance of their classic song.

The album is titled "Exodus" and will mark "The Thong Song" singer's first project in almost a decade, and his 4th overall.

Sisqó's team says the music is so electric, that it needs to drop when it’s hot outside ... so they're eyeing a late spring/early summer independent release.