JoAnna Garcia Swisher, Heather Headley, and Brooke Elliott can’t stop giggling thinking about the first scene of Sweet Magnolias Season 3, and it all has to do with…water?

The season picks up immediately after the action of the Season 2 finale, with the whole gang returning home from the big fight at Sullivan’s that ended with Cal’s (Justin Bruening) arrest. His lawyer, Helen (Headley), bails him out, and she, Maddie (Swisher), Dana Sue (Elliott), and sous chef/Helen’s beau Erik (Dion Johnstone) bring him home.

It’s a serious scene, which you can watch above, but there’s one specific element that has stuck with the star trio ever since they filmed it. In June, Swisher, Headley, and Elliott told Tudum that they couldn’t stop laughing while watching Elliott’s character fruitlessly try to comfort her friends with glasses of water during the tense scene. For whatever reason, Swisher forcefully declined — and that became a running joke. 

Hydration is important, but is it that serious? Even though no one took the proffered beverages, “the best part was that [Elliott] was still committed,” Headley said. “When she was off-camera, she didn’t even have the tray but she walked the water over to keep us in the same rhythm. So she literally picked up no water and passed it to Jo, [who] declined the water. But now we’re watching it and I see her hand Jo the water, and it’s like — ‘Why is she so mad at that water?’ ”

Somehow, said Swisher, that interaction made them all laugh “so hard.” But that’s probably because it was another funny moment between the on-screen best friends that spilled into their real-life friendships. “The guys got a little glimpse into what margarita nights are like with the three of us, and it’s just off the rails,” Swisher said. “Half the time, it’s shocking to even get through the scene.”

Unwanted beverages aside, the scene sets up the obstacles that the Magnolias will face in Season 3 — Helen and Erik need to talk, because of the whole proposal from her ex thing that no one else knows about yet; Cal’s remorseful and willing to walk away from his silent partnership in Sullivan’s to avoid damage to its reputation; and, after Dana Sue goes home, she and Ronnie (Brandon Quinn) talk about the most mysterious cliff-hanger in Season 2 — the appearance of woman whom all the Magnolias seem to know and seriously dislike. 

As soon as their daughter, Annie (Anneliese Judge), heads to bed, Dana Sue asks Ronnie, “When the hell were you going to tell me Kathy was back?”

Who’s Kathy? And why does Ronnie know her? And most importantly, what did Kathy do?! Find out when Sweet Magnolias Season 3 debuts July 20.