i think there are a couple factors at play here

1) seho's attitude was disrespectful, i don't think there's any gray area there. whether or not seho meant it as a joke, it was in bad taste.

-the burger joke, he could have followed up after making the leftover joke instead of completely ignoring kookie, maybe then it would have been funny.

-and here it got to the point where he made the other cast members uncomfortable. cutting kookie off wasn't funny, it was just rude and dampened the atmosphere considerably.

2) kookie. our lil bun. i think he was feeling overwhelmed and the lack of support didn't help. there are a few moments where he legit looks like he is going to cry, but that's partially because he's new to all this and wasn't able to mask his emotions. not faulting him for it, but its just something celebrities learn to do. he pulls himself together for the rest of show, but its those moments that armies will hone in on and the over-protectiveness comes out.

3) over-protectiveness. its bound to come out. maybe some armies were expecting too much, expecting kookie to be babied, but imo seho crosses that line again. sure, he doesn't have to baby kookie, but at least make the kid feel welcome yea? just look at how happy bts was when they were on running man.

you mentioned yugyeom so i'll talk to that too. got7 treats and jokes with yugyeom like that because they are close. there are certain things you can do and say BECAUSE you are close. like, i shade my friends left and right, but i don't do that to strangers, because that would be rude. if anyone disrespected yugyeom (not saying exactly this situation) i can only imagine how got7 would react.

i feel like its okay to expect an apology for this situation cause kookie is visually uncomfortable, but i also feel like it should stop at that. let seho know and he'll do better.