when stimming goes wrong

if anyone has any info or knows anything pls lmk, my oldest is especially begging to go out bc he has always gone out before (where I lived before was more rural & didn't have foxes, or not so close to the house) so I don't want to keep him in unnecessarily bc he's sad about it

for context: my eldest cat is v street smart, has been going out all of his life, generally careful when out & about, big hunter, but he is a senior boy now & much slower but still begs to be let out. my youngest cat is v curious & has only been in the garden in my arms so far