"Please welcome Jenna Dewan Tatum ... Jenna Dewan, sorry," she said while calling her to the stage. Though the interview with Dewan, Jennifer Lopez, Derek Hough and Ne-Yo then proceeded as planned, DeGeneres couldn't let her mistake go and later apologized for her screwup.
"I have to say, before we go to break, I'm so sorry," Ellen told her guest. "I introduced you and it was such a habit, and I have to say the way that you and Channing are handling everything is beautiful for your daughter and the statements have been great. And I apologize. I just have known both of you for so long, and I'm so used to saying..."
"I know, thank you," Jenna responded. "Honestly, thank you and everybody for all the love and support. It's truly, so moving, so thank you. It's all love!"
The duo -- who share daughter Everly -- announced their separation in April. "We fell deeply in love so many years ago and have had a magical journey together. Absolutely nothing has changed about how much we love one another, but love is a beautiful adventure that is taking us on different paths for now," they said in a joint statement at the time. "There are no secrets nor salacious events at the root of our decision — just two best-friends realizing it's time to take some space and help each other live the most joyous, fulfilled lives as possible."
Dewan revealed that the couple's daughter spent a lot of time with her on set of the NBC reality show, watching them rehearse for a group number they'll all take part next season.
"She wanted to be the judge, so we literally gave her a piece of paper, we did our performances and she's like, 6," Dewan said, referring to Hough. "You got a 6 and I got an 8. She was a tough judge."
The rehearsals went down at J.Lo's home, which Ne-Yo said was more "like a city block behind a gate." When she downplayed the size of her abode, he added, "That is a lie from the pit of hell. When there's like an east wing and a west wing, you can't call it a house anymore. It's like a small museum."
"We weren't like having a dance-off, we were dancing together. I look crazy. I don't know if you saw this, she just takes me around the whole party and starts pushing everyone out of the way, like 'Watch out, J-Lo's here,'" Lopez explained. "She did this to Leonardo DiCaprio, how many people were there? It was like the wax museum, it came to life at night."
She was also asked whether A-Rod is a good dancer. "He's a good dancer," she answered with a sly smile. "Listen, I've been with people who can't dance at all. He's not that guy. He can dance, he loves to dance, which is what I love."
Last, but not least, the entire "World of Dance" crew played a game called "Stuff Your Dance Pants," where they competed against each other to stuff as many balls in their "dance pants" in 45 seconds. Things got out of control, fast.