Jennifer Aniston, Brad Pitt Get Steamy in 'Fast Times' Charity Table Read

Jennifer Aniston and Brad Pitt got reacquainted in a virtual wet dream, and if you think that's awesome ... wait until you see how Julia Roberts, Sean Penn and Shia LaBeouf reacted to it.

The exes everyone wants to reunite actually did get together Thursday for a table read of "Fast Times at Ridgemont High" on Facebook with Jen reading the Phoebe Cates role of Linda Barrett ... and Brad played Judge Reinhold's character, Brad Hamilton. And, the best scene, that has everyone talking, is that sexy pool/masturbation scene. Y'know ... KNOCK, PEOPLE!!

You could cut the sexual tension with a knife as Morgan Freeman, of all people, narrated the scene describing ... leading up to some heavy flirting between Jen and Brad's characters.

The scene had everyone involved grinning from ear to ear ... Julia, Shia (who voiced Spicoli's character) ... plus other cast members John Legend, Ray Liotta, Matthew McConaughey, Jimmy Kimmel and Dane Cook.