Ben Affleck and Jennifer Lopez Reunite for 'Kiss of the Spider Woman' Premiere

Ben Affleck and Jen Lopez are back together ... at least for one night only ... but it's strictly business.

The famous exes reunited Monday for a movie premiere in New York City ... showing up for the first screening of "Kiss of the Spider Woman."

Jen stars in the musical and Ben serves as an executive producer. Artist Equity, the production company he shares with Matt Damon, helped produce the flick.

Ben and Jen mugged for the cameras, standing shoulder to shoulder ... and he even wrapped his arm around her, resting his hand on her waist.

As you know ... Ben and Jen's 2024 divorce was actually finalized while she was filming the musical.

J Lo is also on the record saying the movie is all about escapism and it helped her navigate one of their hardest times of her life.