So he's scared of an outside crowd but perfectly fine being on ships with thousends an in closed parks
As someone who genuinely does get huge anxiety with crowds, being outside is actually a ton better for me than being inside someplace or being in somthing that's closed like a park an only has the one entrance/exit, especially if it's a outside place I can sit down at as well
He didn't go because its more like
1 he can't be bothered with it
2 lazy
witch will still be in bed an stans would wonder why she isn't there
3 J would be a CHILD you know maybe run about, babble to others, join in with other kids etc
4 it might actually show that J isn't the little space enthusiast they go on about him being