A few days ago TWICE's Nayeon and Jeongyeon talked about BLACKPINK's concert on a vlive after a fan asked them about it.
"It was awesome", commented Jeongyeon. "But we only got to see the middle part due to our schedules. I didn't get to see DDU-DU-DDU-DU!" showing regret for missing it. "I can't believe i didn't get to see DDU-DU-DDU-DU."
"Momo and I were dancing like crazy and our manager took a video of us with his phone." added Neyeon.
Apparently Jeongyeon went to the concert with Chaeyoung, after Nayeon and Momo.
The topic starts at 12:50 in the vlive down below.