"It was absolutely fun. Brad and I are buddies, we're friends," she replied. "And we speak, and there's no oddness at all, except for everyone that probably watched it and was wanting there to be, or assumed there to be."
She added that the two "had fun" and were happy to do it to benefit "a great cause."
Elsewhere in the interview, Stern also asked about the big HBO Max "Friends" reunion revelation that Aniston and costar David Schwimmer were romantically interested in each other in real life while playing on-screen lovers Rachel and Ross. While they were both "crushing" on each other, they swore they "never crossed that boundary" and made it physical. Howard, as only he could, wondered why she didn't "bang" Schwimmer at the time.
"He was lovely, David was great," she said of her costar. "We were in relationships and it was always never the right time and it wouldn't have worked. The beauty of that was that whatever feelings we had we just literally channeled everything into Ross and Rachel and I think that's maybe why it resonated the way it did."
She then said both Courteney and Lisa could "vouch for" her, as Cox said everything Aniston was saying was true.
"Howard's not going to believe me," added Jen. "No, I would proudly say I banged Schwimmer if that happened. But no."
The interview comes in tandem with a cover story for PEOPLE, in which Aniston also opened up about her current love life.
"I'm in a really peaceful place. I have a job that I love, I have people in my life who are everything to me, and I have beautiful dogs," she told the publication. "I'm just a very fortunate and blessed human being."
She said she would "absolutely" not be popping up on any dating apps and is "going to just stick to the normal ways of dating. Having someone ask you out. That's the way I would prefer it."
When asked if she would ever get married again, the twice-divorced star replied, "Oh God, I don't know."
She added, "It's not on my radar. I'm interested in finding a fantastic partner and just living an enjoyable life and having fun with one another. That's all we should hope for. It doesn't have to be etched in stone in legal documents."