Rob Lowe, 60, just revealed he "briefly had a thing" with fellow Brat Pack member Demi Moore, 61, back in the 1980s!

Lowe revealed the tidbit while talking with Kelly Ripa on her podcast "Let's Talk Off Camera."

Ripa told him how much she loved the 1986 movie "About Last Night," in which Lowe and Moore's characters move in together after just a few dates.

Kelly told Rob, "You two have crazy-good chemistry," and he replied, "Of all the stuff I did in the '80s, if I had to pick one, it would for sure be 'About Last Night.'"

They went on to discuss the 1985 hit "St. Elmo's Fire," which also starred Rob and Demi, along with more Brat Pack celebs.

Kelly asked of Demi, "Did you have a crush on her? Did you guys ever date? Did you all date each other? Was it like, just -- was it a big romp?"

Lowe joked it was a "big, big sex orgy" among the cast.

He went on, "I mean, Demi and I briefly -- I'm not telling tales out of school -- we briefly had a thing."

Rob pointed out that the fling happened before Demi was engaged to their "St. Elmo's Fire" co-star Emilio Estevez.

He insisted, "Look, anytime you put young, 20-something men and women together, hookups are inevitable."

Lowe and Moore parted on friendly terms. He even attended her wedding to Bruce Willis.

These days, they have texted about a "St. Elmo's Fire" sequel!

He said, "It's moving along. It's going a little more slowly than I would have liked, but that's a good thing because we're trying to find the right writer and the right story. But all of the actors, everybody, is on board. Everybody's excited."

Lowe said of the original, "It spoke to where we all were in our lives. Will we ever have the kind of deep friendships coming out of college and coming out of our early 20s? Will that last in our lives? And where are we headed now that we're really adults?"

As for a sequel, Lowe shared, "I think the theme of 'St. Elmo's Fire' today is that it's never too late for happiness. You know, because our kids are out of school, and maybe some of us have been divorced... all the things that you deal with as you get to our ages. This is an opportunity to explore those themes with characters that people know and love."

He added, "I actually think there's a lot to be said about why we're doing it, and I'm super excited about it. Hopefully, we can pull it off."