@@cece2318 he said on their monthly review. he did not actually said he watched it. rather, he said that just sees a lot of the "jungwon teasing jay for five minutes" videos in his feed randomly.
Idk about this part but Jay draping his arm over Jungwon is such a common thing that when they did a photoshoot like that the members just oh that's a common pose for them. They're like that all the time. Such a beautiful friendship.
It was because Jungwon had a mission to do at their Studio CHOOM filming: he had to have one of the other members poke his cheek without them knowing, and he failed when they all found out but still kept trying to force the members to poke his cheek so he wouldn't have to do the punishment. And Jay was really gentle, when I've seen other compilations of the members being funny/messing around, I've noticed nobody teases/slaps/scolds the others as gently as Jay does. It's one of the hundreds of reasons I admire him. Hope this helps! God bless :)